WATERLESS LITHOGRAPHY USING COMMON CAULKING SILICONE

A new process of producing aluminium lithographic plates using ordinary silicone rubber
as an ink rejecting surface
.

Developed by Nik Semenoff, June 1990, University of Saskatchewan, Saskatoon -
Updated December 2014

Historic background

Alois Senefelder discovered "chemical printing" over 200 years ago and since then lithography has relied on the principle that grease and water do not mix. While it has allowed lithography to replace most other media in the commercial printing area, the use of water in the process has produced a number of nasty problems for the printer. Because of this, printers have long dreamed of a system, which would completely eliminate fountain solutions and all the inherent difficulties. A number of years back, 3M had tried to develop a waterless system for the commercial printing trade; but after investing a considerable amount of money, they sold their patents to a Japanese company. In the late 60's, Harry Hoehn of Long Island, NY, experimented with the then available RTV silicones, probably inspired by the 3M material.  Toray Industries, Inc., now markets a waterless process that is capable of reproducing very high quality photographic images, using either positives or negatives.  Since theirs is completely a photographic process, the image must be first drawn on paper or other substrate and replicated with a copy camera. Hand drawn images direct on plate are not possible, but images on Mylar exposed to their positive plates is the best process. The cost and availability of Toray plates puts them beyond the reach of most artists.

Close ups of a regular 150 LPI screen traditional offset poster, next to a 375 LPI Toray waterless, next to a 600 LPI poster

Many years ago (1982), I became interested in the waterless concept and planned some experiments to try out some of my theories. My good intentions were put aside for a number of reasons and only in 1990 I started my research. To my amazement, the very first plate produced a very respectable print and became the basis of my process. It was Jeff Ryans’ presentation of his work with Toray plates at the Tamarind Symposium in 1990 that sparked my own research. I must add that I did not know of Harry Hoehns' work until 1992, when a printmaker gave me a much copied paper of that process at an international conference we were holding at the University of Saskatchewan.

While it is commonly believed that grease and water do not mix, lithographic ink and water do in fact blend to some degree to make the plate work better, but too much water in the ink produces a "short" ink that is difficult to use. Some art printers believe that a small amount of water that becomes emulsified with the ink will produce better prints, and control this in a number of ways. The fact that water has less cohesion and viscosity than ink, the separation of the two takes place at the water layer, leaving a few molecules of water to be taken up by the ink roller. While water has been the basis of the lithographic process, elimination of fountain solutions would be better for the media. What was needed is a material on the non-printing area that would not be liquid at the time of printing.

Grease drawing materials reacting to stone and metals.

Another problem common to lithography is the chemical inter-action at the surface of the metal plate. The sensitive metal surface will bond with any carboxyl molecules that are present in many greasy materials and some gums, thereby producing the areas of image and non-printing background. It is the remaining portion of the molecules that either accepts or rejects grease or water, depending on whether a CH (hydrocarbon) or OH (water) segment is presented to the ink roller or dampening sponge. Because the metal will accept either molecule, (as long as the carboxyl portion is present), the plate can go blind, or become too dark, as the materials are disturbed and replaced by the other type of molecule. If the two areas depended on totally different chemistry, a more stable plate would be the result.

The difference on how grease and toner reacts to gum etch

A process that would eliminate some or all of the toxic materials now used by printers would certainly be highly desirable. Materials should also be easily available and not too expensive. Anything that would simplify the processing of plates and produce long running clean images from direct hand drawn plates could become an important addition to the artists’ lithographic process.

Properties of silicon

Silicon is one of the most abundant elements in the universe. It is present in many rocks and is the major constituent of sand. We have for centuries used it to make glass and have manufactured lenses, laboratory utensils and other scientific equipment from it. Science has converted silicon into many forms ranging from a soft rubber-like material to hard-as-stone compounds. It is responsible for the transistor and the computer chip that makes radio, television and computers everyday consumer products. In many forms, it becomes a very stable material that will endure for many decades.

I used silicone to make a wax model to centrifugal cast a sterling pendent for my daughter in memory of her angle fish

As a rubber-like compound, it is used as glue and a very effective sealer for water as a caulking compound. Some of these products retain silicones affinity for itself, and some other materials -- and the rejection of other compounds. Taking advantage of this characteristic, we can produce a non-printing layer on appropriate substrata to produce a waterless lithographic plate. The availability of many commercial sealing products gives us a freedom of choice and at the same time adds to the confusion of which works best for our purpose.

Silicones are organic polymers, molecules that consist of mainly of silicon and oxygen, which can be modified to produce a great number of wonderful products for our daily use. As printers we are only interested in the common caulking silicones that are used in the construction industry as sealers and adhesives. Even these come in a number of varieties that can confuse even the most chemically gifted, so I will refer to only two main types that I have used. The caulking silicones we are interested in are the unpaintable variety, and this should be noted somewhere on the container. I would suggest you purchase yours as cartridges to save money, instead of small tubes, as you will likely go through a fair amount if you print regularly. These products are designated as RTV, for Room Temperature Vulcanizing. They cure by absorbing moisture from the air, which is used as a catalyst. While two part silicones are available, these have not made an impact in printmaking.

Another type of RTV silicone does not produce acidic acid and known as neutral cure and these are becoming more common. While promoted as having better adhesion to painted surfaces and plastics, I have found them to not be quite as good at rejecting ink. Japan produces a non-acidic silicone that I have found to be superior to the varieties available in North America.

The material used

My approach is to secure a cartridge of clear silicone seal from the hardware which is known to be unpaintable and stated to be so - on the container. These are amongst the first silicone sealers and glues made available to the public and the commonest, but are now being supplemented with paint able and water-based versions. It is important to acquire the non-paintable product in the standard solvent type of sealer. The large cartridges are the best buy and the easiest to manipulate. Many varieties are on the market but I have found that those sold as ordinary caulking to be the best for curing and excellent in rejecting ink. Various brands are available and there is some difference in the subsequent silicone layer which can have an effect on the type of ink you may use. Since it was impossible to acquire all the brands which are or will be on the market, you will have to test those you think might work, as some of these could produce even better results than those I've experimented with. In the past, I unquestionably recommend Dow-Corning silicone for three reasons; it has a screw in plug for better storage, is tough - making for a better ink rejecting surface, and is consistent in quality. Lately, in my part of the world, Dow-Corning silicone which I originally used has been hard to find and only available from construction contractor suppliers. Since all silicone rubber materials are known to have a self-life of about 2 years, you should look for stores with fast turnover of products. Look at the "Use by date" printed on the cartridges. Today, the capping method used by some silicone manufacturers do not use a large screw on system, but one that is meant to have the pointed end cut to the best shape for spreading the caulking gel. If they have a screw cap, do not cut the plastic cap as that will allow hardening of the silicone inside. Just squeeze some silicone up into the hollow to reduce the amount of air that will thicken the surface of the silicone exposed in the larger hole in the cartridge.

While it is more economical to purchase cartridges, tubes may be better for amateur printmakers because of silicone self-life

In the last couple of years, I have been using Japanese silicone that a Japanese printmaking friend has sent me. She gave me three cartridges ranging in price. The cheapest come to much less than any North American silicone, but it worked much better than Dow Corning. These silicones do not have the acetic acid smell, bond better to aluminium and reject ink much more in my opinion. They also gel faster in a partly used container of diluted silicone, making it possible to produce a poorly adhered rejection layer on the aluminium plate if the batch is too old. I keep my diluted silicone in the freezer, but it still will become too thick in time.

Because the silicone is very thick as it comes from the cartridge, it must be diluted to a usable solution. I have found that odourless paint thinner is the best solvent that is easy to come by; at the same time better controls the rate of drying when applying the silicone. Having the aromatic hydrocarbons removed, it is less offensive in the studio and certainly much safer than ordinary hardware paint thinners. Use a small container with a tight cover if you intend to use the silicone over a few days. Start by adding only a little solvent and stir it in. Add solvent to mix into the proper consistency. The viscosity of the mixture is a matter of taste but I think a thinner solution is better as it cures faster. The silicone should be diluted to the consistency of very light syrup. For smooth backs of recycled plates, I use 30% silicone to 70% odourless solvent.  It is better to apply two or three thin applications rather than one thick one to get the best desensitization. Some substrata such as coarse ball grained plates may require a thicker coat with a more viscous solution, so experiment for the best approach - which will only come with experience. I rarely need to apply more than one coat of silicone on aluminium plates, especially when I use the back of recycled plates. With the Japanese silicones, I have been using two more diluted coats to make sure there are no too thin areas on the plate. I can tell by the smoothness of the second coat if the layer is perfect for editions.  A perfect film will reject a properly modified ink off all the area of the plate - not having to roll off the plate when there is a line left where the roller stopped.

In my early research, I have discovered that the supplier of the odourless paint thinner that I was using must have changed their formulation. The solvent had a much stronger odour, but it in fact seemed to break down the particular silicone I was using, into areas that ruined my plates before I realized what was happening. It seemed to separate out the rejection oils from the rubber, allowing the ink to tint the background clear areas; but more important, it would blind the image as the roller went over it carrying the oil. I have found many brands that work, but you should be aware that this sort of thing can happen as we are using common materials not intended for printmaking.

It also depends on how the maker of the odourless material set up their fractional distillation system. In some odourless solvents, I feel a higher temperature has allowed more oily molecules to be present, which do not evaporate from the silicone film very fast. While common paint solvents can dilute the silicone very effectively, there are some toners that are actually dissolved in these solvents. Most are not, but the stronger odour of Varsol can be problem for some printers. Although more expensive, the odourless thinners from the art store work very well - if common odourless solvent is not found in the hardware store.

Depending on the brand, the thinned solution can be placed in a well capped container and kept for a long time. By using thinner silicone and applying two thin coats, a sufficient layer can be built up quickly with the aid of a heat source such as a hot air paint stripper; this overcomes any missed areas. I had taken to using Dow-Corning #999-A, a professional material which is available from Canadian building contractor suppliers. This has now been replaced with "Trademate", available at building suppliers. You can purchase a supply and keep the cartridges in your freezer, where it will keep for a much longer period. Remember, silicone has a shelf life. Hopefully, a silicone similar to the Japanese product will be made available to waterless printmakers across the globe. It really is surprising material.

Stirring with a stick is inefficient, so purchase a latte mixer that you should modify by removing the spring

Diluting the silicone while stirring with a stick is inefficient - and boring as well. I have tried many small motorized mixers to prepare solutions for coating plates, but the recent interest in Latte coffee has brought forth a number of small fast revolving units with the paddles designed for making froth. To make mixing easier, I now use one of the new motorized froth makers popular to make cappuccino coffee. You should remove the spring like wire first as it will just become clogged and not be effective unless cleaned, which is nearly impossible to do. To get a bit of action from these fast revolving units, I just bent the circular section so it is no longer sitting at right angles to the shaft. If you make too large an angle and happen to get a very fast motor, this can throw out solvent from the container as it gets filled. This we don't want while mixing the silicone as it introduces humid air, which will produce a mix that will tend to gel in the container much faster. On some units made of plastic, I remove all the protrusions but two - one on each side of the shaft. When mixing the silicone in a small bottle, fast large revolving paddles will throw the mixture from the container every time.

Start by putting into the container a reasonable amount of silicone to produce a 30% solution. Add only enough solvent to cover the glob and stir the two until it starts to partially come apart. Now you can use the motor of your unit, trying to break down the gel into smaller pieces. After the glob has started to be broken down and less viscous, add odourless solvent and keep stirring. Depending on the viscosity of the silicone, the final fluid should have the consistency of light syrup. If you are using grained plates, the viscosity should be higher than for smooth backs of recycled plates. If too thick, you will lose all the fine detail on your toner wash and also make it harder to spread the silicone into a thin film.

Drawing the image with water based materials (The simplest and safest method to get an image)

There is on the market a number of water soluble crayons and drawing pencils that make perfect images similar to grease crayons. The best is Staedtler Omnichrom #108-9. Draw on the plate with these water soluble crayons; feel free to remove mistakes with water if need be. As long as the bonding agent for the crayons is removed, the plate will take silicone. If only water soluble materials are used, they can even be removed (washed out) with water after the silicone coating is applied and cured. The plate is then ready for printing.

Any water soluble drawing material will mask off the plate surface to reject the silicone

There are a number of other water soluble pencils that can work, but these have to be heat set so they become insoluble in odourless paint thinner. Even some washable children's felt markers and Crayolas’ “My First Crayons” will work if heat set. As you heat these drawing materials, they at first will take on a glossy look - then become dry as the image is bonded to the plate. Experiment with the pencils, crayons and felt markers you have on hand, many may work. Neocolor II by Caren D'Ache is another that produces a darker mark but is slightly affected by the coating solution unless heated. Many ballpoint pens will produce a beautiful thin line when used on the smooth backs of reclaimed plates. These images have to be heated to resist the application of silicone. 

Common molasses (Treacle) with colorings matter and some retarders make up a very exciting imaging material by using it as an ink for a version of a monoprinting technique. Variations of this mixture can be used as an image protector as well when one needs to add more silicone to a damaged plate. Start with molasses from the grocery store. Make up the binder solution with equal part of molasses, Golden Acrylic Retarder and polyalkylene glycol (available as DOT 3 brake fluid). Into this mix in Prussian blue dry pigment and some magnesium or calcium carbonate to get an ink like viscous product. This can be rolled out on a slab into a thin even film and the drawing made on paper placed over the “ink”. Draw your image with a pencil so that it will pick up the molasses ink on the other side, making sure that you do not spoil your sheet by placing your hands on the paper. The image will be a ragged line that can add character to the drawing. It is a simple matter to transfer the image to a plate and dry it thoroughly with a heat gun before siliconing the plate.

For solids and pen work, ink made up of water soluble glue and a colorings agents works very well. I found dextrin better than gum or glues because of the fluidity of the adhesive. Make up a reasonably viscous mixture of dextrin in hot water and let cool. Add cheap Sumi ink to give you a good black. This ink can be applied with brush or pen and can be removed with water if changes are needed. I suggest adding some kind of anti bacteria compound to prevent the ink from souring. I use this mixture with red dye in my Rapidograph pens for clean even lines. If sufficiently colored, water soluble mixtures are terrific for use with an airbrush.

Producing Reverse Lines and Flat Areas

An interesting technique that could only be done on stone was to scratch through a solid area made with grease tusche before the gum-etch was applied to produce a white image on a colored background. This technique is not possible on metal plate with traditional lithography. In waterless the procedure is simple and can be used in two ways.

Reverses are possible but you must plan ahead in your projected edition

Apply waterbased glue or acrylic floor polish as the background area and scratch through it after it has dried. When silicone is spread over the plate, it will enter the line and produce a white image on the print.

A variation on making this sort of reverse is to do your drawing with common wax crayons, toner, Future polish or lacquer materials. Cover the image and area with waterbased glue and let it dry. The image must be completely removed with appropriate thinners to expose the plate surface. When silicone is applied to the metal, it will bond to the plate and form a white image. The glue is removed with water before printing to allow inking of the negative area.

Using toners and plastic materials

Using my toner tusche wash process on aluminium grained plates or recycled smooth plates is another approach. Dry copier toner images have become a common worldwide printmaking technique after I introduced it in 1985. There have been minor changes to toner powders over the years, becoming much finer to accommodate the newer 600 and 1200 dpi machines, but the same principals apply for using all toners. Toners today contain all or a large percentage of black iron oxide instead of lampblack like the earlier material. Artists know iron oxide as Mars black pigment in oils colours. The concern that toner is toxic because of carbon black was basically unfounded as each particle is encapsulated within a plastic. In fact, plastics make up most of the bulk and pigments range around 10% and less for color toners.  It is a dirty product that most people would not like to get on themselves, and making much toner dust is just plain carelessness.  Spilled toner can be easily cleaned up with soap and water.

Toner can produce more textures than possible with traditional grease tusche and can be manipulated on the plate until satisfied with image

With toner, draw an image as a tusche wash - toner chalks can be used as well. Any material that will not be affected by odourless paint thinner, yet can be dissolved in acetone or water is a likely candidate for drawing. Shellac, floor polish emulsions, and cut Mac-tac film are good for certain type of images. The Mac-tac can be stripped from the plate surface after the silicone has been cured. Spray lacquers can be used for air brush effects, as long as the lacquer can be removed. For pen line work, a simple ink made up of one of the new acrylic floor polishes (Future) and Sumi ink for color, works better than liquid tusche or autographic ink does in traditional lithography. This quick drying plastic material can also be used to produce large solid flat areas. Since the grease reservoir is not needed or desirable, all that is necessary is to produce a mask to protect the metal surface. Acetone will wash out or "develop" the plate for printing (see my toner paper or the Leonardo article published in 1987). Unless the waterproof characteristics of acrylic emulsion are needed, I recommend you use water-soluble materials for flats.

Using traditional grease materials

Common lithographic grease crayons cannot be used directly with the waterless process as they will be dissolved by the solvent present in the silicone coating solution. Since some artists prefer the effects of traditional tusche washes and grease crayons; these materials can be incorporated into the waterless process. Because of the nature of these materials, the process requires an additional step or two to take full advantage of the technique. Vinyl lacquer base or other masking lacquer material will be required, as well as plain gum Arabic.

The concept of conversion of grease images can become an important technique using any oily drawing material

The image is produced in the conventional way using stick tusche for washes and crayons for drawing. Any materials that will produce an impervious layer to the water based gum should work. Ordinary marking pencils with high wax content and felt markers are also all candidates as drawing tools since no acid etch is used.

Talc the image as usual and apply less viscous plain gum Arabic all over the plate. Since we are not etching the plate in any way, other gums or water soluble glues may work. All that is needed is some form of mask to protect the non-printing area from the vinyl lacquer which will be applied as another temporary mask. Buff the gum down to a tight film and dry. There is no advantage to let the image gum sit on the plate as in traditional lithography, so as soon as the gum is dry, the image can be washed out with lacquer thinner or an acetone and odourless thinner mixture. Apply lacquer and after the vinyl has dried, the gum can be removed with water. Make sure the lacquer is completely dry by going over it with a heat gun.

You can use a coat of my special vinyl lacquer and buff to a tight film. I use a special lacquer for my positive plate process and found it works well as a vinyl base for traditional lithography and this technique as well. It consists of Nazdar vinyl screen ink and their slow retarder for that ink. I have chosen blue and red for research and both work well. Get the ink with the strongest pigment and dilute it to a viscosity that allows easy spreading and buffing that consists of 1 part vinyl ink and 2 parts thinner/retarder. Spread to a very thin even coat, making sure that he outside edge of your coating is not thicker than the image. The products I have are the ones still sold under the “ink dezyne” label; Nazdar has bought out the company but I am told they have retained the vinyl screen ink under the same numbers. Make sure you heat the image with a paint stripping heat gun to make sure it is well cured.

Wash the plate with water to dissolve the gum, making sure it is completely free of any gum film. Silicone rubber can applied as on any imaged plate, then buffed down. From now on the plates are handled the same way. After constructing the silicone layer, the plate is washed out with acetone developer to remove the image lacquer and expose the metal. Printing can proceed from here.

Applying the silicone coating

Place the plate on a flat surface with pieces of newsprint or large scrap paper underneath it, with enough paper sticking beyond the plate to keep the table clean. After the toner image is set with heat or white gas - or when water soluble medium is used - the silicone solution, which has been thinned to the consistency of light maple syrup, is spread over the entire plate and buffed down. Pour a small amount of silicone unto the centre of the plate and spread it with a piece of scrap foam urethane or some soft material, making sure it doesn’t remove any drawing materials. Damage can be noticed by a change of color if unset toner or dark pencils are used. Unfortunately damage to the image may have already been done - but not in all cases. For coating the smooth backs of aluminium plates, I use about 20% caulking silicone in odourless paint thinner. Ball grained plates could use a slightly more viscous mixture of 25-30% silicone. Use small foam rubber pads to apply the silicone, as they are much gentler on the image than cloth or paper. These can be acquired as scrap from upholstery shops or bought from department stores selling such products.  Old pillows and mattresses are a perfect source for this useful material.

You will have to remove much of the excess silicone before buffing takes place, so I use previously used facial tissues as there is still much area with no cured silicone around the edges. These used tissues are placed in a container and added to as each coating session ends. A handful passed over all the plate removes much of the fluid but there might be wet areas when viewed by reflected light. For the final buffing, use a piece of soft foam urethane about 3 x 5 inches (8 x 13 cm) size; covered one side with a double layer of facial tissue.

Thin out your silicone so that the finest detail can be printed. Buff the silicone film to a polished surface with padded facial tissue

It is important to leave nearly a mirror smooth surface as any ridges of silicone can produce tinting in that area. I suggest you place a light near the coating area so you can observe the buffing operation more carefully by reflected light. Stop buffing when the surface is smooth as farther effort will start to ripple the silicone as it starts to setup. Buffing becomes an art and one of the more important steps for producing successful plates. While silicone cures with humidity, there is still the odourless paint thinner that has first to evaporate from the thin film. If possible, just set the plate aside and let it cure overnight, which will produce an effective ink rejection film. With the very thin film of around 3 - 4 microns, curing is fast after the solvent is gone. For immediate use or research, dry the entire surface with a paint stripping gun by slowly going over it side to side, much like mowing your lawn. If there is any doubt about the integrity of the silicone layer, I would put on another coat after the first has cured. Do not produce too thick a layer as it will be difficult to develop the image and you will harm the silicone surface during a difficult washout. Too thick of a layer of silicone is the cause for the loss of fine tints, producing very contrasty images. After all, silicone caulking is designed to keep surfaces and cracks free from water and is superior in that way. Remember that when applying your silicone film.

I have found that the silicone becomes extremely durable if allowed to cure for some time; as my older test plates seem to resist all attacks on the coating. Although printing can proceed immediately, leaving the plate to cure overnight is not a bad idea.

Silicone Intaglio - or is it Jeff Ryans' original research into waterless lithography?

Waterless lithography has been known as Driography, the original name given to it by 3M in their patents. Toray chose to call it waterless lithography and I have as well, to indicate to fine art lithographers that they do not have to deviate too much from their craft. Others have started to use and promote the process as Siligraphy and Silicone intaglio. Siligraphy to indicate that is has some relation to silicone. Silicone intaglio to suggest that the image is very slightly below the surface of the plate, so intaglio comes to mind. These are all basically the same process, building on the 3M discovery and my independent research that produced the method and techniques discussed in this paper. To my mind, silicone intaglio is simply a step away from what lithographers have known from the very start of the craft and taking away the credit Jeff Ryan deserves for his original work with Toray plates. I believe by renaming a process is attempting to take away credit from the original inventor.

While I have not discussed this simple imaging method before in this paper, I have shown it to printers at my workshops as it is a well know principle known to printers from the early days of lithography. Even on stone, the printer would first gum etch a plate by adding pigment to the gum so the scratches can be seen much easier. After the surface is cut with an etching needle, asphaltum was rubbed into the image and rolled up as a processed plate. Metal plates worked the same way and many artists made simple additions to an image by scratching through the desensitised gum layer. Today, this technique is being promoted by others as an original method, using commercial Toray plates and suitable inks. They are also promoting what is basically waterless lithography within their process.

With the cost of Toray plates, I am surprised an artist would use them for such a simple technique. In place of purchasing Toray plates, one can use the backs of used aluminium plates, which have been first coated with silicone. A number of artists at my workshops have used the technique to produce beautiful delicate images, which would print large editions. See my paper on recycling plates over and over again for a method of reusing plates. After the edition is printed, the silicone can be removed and the surface scrubbed with a coarse 3M scouring pad to eliminate the scratched lines on the surface. I have found any trace of a line will not become a problem, if the stripping and cleaning was effective.

Stripping off the silicone for adding to the image or reclaiming plates

Because silicone sticks so tenaciously to the plate surface, it is more difficult to make image changes than counter etching a traditional gum plate. After much research, I have found a chemical that works. While strong organic solvents will dissolve and remove the silicone, it is difficult to eliminate all traces of silicone from the surface. Even a very thin film will prevent the new image to take hold, allowing for a possible plate failure during editioning. What is needed is a solution that strips off the silicone cleanly and not "dissolve" even a small portion of it so that it can rebond with the plate. While strong acids could be made to attack the metal under the silicone, experiments showed this was not a practical method.

Fluoride compounds are the surest way to make sure all the silicone is stripped off the plate surface. Use 3M pad with carpet backing glued on a block of wood

In the end I have decided to use fluoride compounds as this element attacks silicon on contact. While a weak solution of hydrofluoric acids works, the dangers of using this liquid chemical goes completely against my search for less dangerous materials. After some experiments, I have found that a very weak solution of ammonium bifluoride and an acid does the job perfectly and should not be too dangerous in the concentrations I propose. A small amount of ammonium bifluoride crystals are dissolved in acid and water to form a solution. Do this in a plastic container as fluorides attack glassware and metals. To force students into putting on rubber gloves and so prevent any absorption of the chemical, add a large amount of a strong red dye which would stain the hands - it also aids when applying the stripper. One can also add acetone to act as a wetting agent on the silicone and help remove ink but do not need it for well cleaned plates. Wheat flour can be added to increase viscosity to reduce beading on the silicone surface if one is trying to recycle a ball grained plate surface - by why bother. When using the backs of recycled plates, the silicone layer is much thinner and is more easily removed, using less saturated solutions of HF and surfactants to reduce beading. The formula which I recommend is as follows:

Ammonium bifluoride crystals                               1/16 oz. by volume

Phosphoric acids                                                        3-4 oz.

Water                                                                            32 - 64 oz.

* Add food colorings to make solution very red

* Add acetone if ink removal is wanted; dispense with the acetone if the image is to be retained.

* Automatic dishwasher surfactant to lessen the spotting that occurs on the silicone film. Use a surfactant that advertises "with Citrus Vinegar" as it seems to survive the acidic solution and lessens beading somewhat.

Simple Wash/Deck

I have also found a perfect product to make a good silicone stripper. In Canada there is a cedar deck restorer sold under the name of “Simple Deck”. Made up of phosphoric acid, it also contains a surfactant that greatly reduces beading of the solution on the rejecting silicone layer and so produces a new surface without blemishes. It can be diluted by a factor of 4-5 or more and still be effective. To this diluted solution, add about a half teaspoon of ammonium bifluoride crystals to a gallon of liquid. You will have to experiment on the amount of “Armour Etch” that is needed to effectively remove silicone.  Glass etching compounds that contain bifluorides are available at stores dealing with leaded glass. 

The amount of chemical can be varied according to your experience and nature of the plates. Use weaker solutions at first, or if you want to retain some of the image. Because of the harsh action of this stripper, it is difficult to hold the image. By applying rosin to the wet ink and heating the plate, more of the image is saved. On an old plate, test the effectiveness of the stripper by applying it to a small area with a pad made from carpet and a wooden block. If there is a heavy coat of silicone, the solution will likely want to bead and no amount of acetone or surfactant seems to help. Keep the solutions moving over the area, this will have the desired effect on the silicone. You will notice a slight resistance to the movement of the pad where the silicone is being removed. After a minute or two, take a wet foam rubber sponge and wipe off the stripper. If the solution is strong enough, the affected area will become wet with water, indicating the loss of the silicone layer. If an ordinary urethane sponge wet with water is rubbed on the area, it is much more effective in removing the silicone as it acts like an eraser. A stiff finger nail brush also helps displace the silicone on coarsely grained plates.

Make sure that the surface of the area where you recycle your plates is perfectly flat. I have holes in my sink that will secure my plates
to make it easier to recycle

Try to reduce the amount of ammonium bifluoride in your solution by now taking a small portion of your mixture and try diluting it with water. There will come a point that the solution is ineffective even after leaving it on the surface for a long time. Try for a solution that will work in 3 - 5 minutes, and so reducing the dangerous chemical to the minimum. Adjust all materials to conform to the typical thickness of silicone you use on your plates.

In the end I have reduced the hydrogen fluoride content to less than .5%. No fluoride gas would be escaping from this mixture. My test solutions read 3.9 - 4.5 pH on my pH meter, but this is due to the phosphoric acid present. It is important that you use rubber gloves to farther reduce the dangers of using fluoride compounds. Ammonium bifluoride is also called ammonium hydrogen fluoride, which indicates that part of the compound contains hydrogen fluoride, or hydrofluoric acid. We encounter fluorides in toothpaste and drinking water every day. At the low concentration in the stripping fluid, and with common sense, I see fewer problems with it than many chemicals we use in printmaking, but special care still must be taken when working with fluoride. Similar chemicals are used by stained glass workers to frost areas of their pieces. With extra care, there should be no problem of using this approach to counter-etching and recycle your plates.

The purpose of all this is to make use of the plate as many times as possible. Because of the very thin silicone layer and the aluminium silicate underneath, it is easy to reclaim the plates, as that layer seems quite susceptible to removal with weak acids. I used to use a counter etch made up of phosphoric acid, with a very small component of hydrofluoric acid. About four ounces phosphoric acids are added to a gallon of water. To this is added about half a teaspoon or less of ammonium bifluoride crystals, to help destroy the silicone layer. This should result in a solution with a pH of around 1.5, depending on the concentration of the acids you use. Even weaker solutions have worked for me and I would recommend you could dilute this formulation even more. I have used a number of aluminium cleaning solutions in place of pure phosphoric acid as these contain the acid as their main ingredient. The very small amount of hydrofluoric acid in solution should not be a concern, as long as gloves and other standard precautions are taken. I like to add some red food colorings to this solution to indicate the danger of the chemicals being used. These days I use the commercial "Simple Deck" for its' phosphoric acid and surfactant content.

Because of the concern in using any solution with fluoride, I had asked our chemistry department to analysis a once available commercial wheel cleaning products and the resulting diluted solution made from these. While the original products contained less than 1% HF, the diluted stripping solution tested at .36%. While this information was dealing with the aluminium wheel cleaning materials, the same ratio of HF in any stripping solution will recycle the plate. 

If ammonium bifluoride in crystal form is available to you at teaching institutions, I would recommend that you make up your own stripper because of the high cost of buying the commercial materials. I have found that it takes an extremely small amount of the crystals to make a useful stripping solution, as long as the silicone coating is thin, according to the best practice of waterless lithography.

To remove old ink, I generally use a solvent made of 1:1- isopropyl alcohol: acetone to certainly get rid of any ink that resists removal. This prevents the previous image becoming lightly etched into the metal because of the resist factor of the remaining ink. With ink removed shortly after printing the edition, the image should be clean enough to start stripping at any time. The silicone stripper etch is poured on the plate and quickly spread to even out the etching action. Using one of the special pads made just for this part of the process, the chemicals are moved around as you see the silicone disappear and the entire surface takes water. With greater amount of phosphoric acid, there can be some foaming on the surface, so you have to keep the solution moving – otherwise it will produce different textures across the plate.  If you want a more abrasive attack on the surface, I would suggest you use aluminium oxide pads instead of the other common abrasives. The bifluoride will be depleted if you use abrasive containing silica, like pumice or silicon carbide; and the acids will be neutralized if kitchen scouring powders are used, as these commonly contain calcium carbonate. I have found the use of 3M red aluminium oxide pads the best for recycling plates when stripping off the silicone.

Once the surface is accepting the stripping solution all over, this indicates that the silicone layer is removed. Flush the surface with plain water and then squeegee off the excess. By applying sodium metasilicate in dilute form, a new layer of aluminium silicate is produced for the next image, as well as neutralizing any acid left in the pores of the metal. If there seems to be some water rejection, use a green 3M scouring pad to abrade the surface of the plate. Flush off with water while running the palm of your hand over the surface to feel any slipperiness as this may leave a compound and prevent silicone from sticking. Squeegee off the water and dry; you have just recycled your plate for reuse.

I should emphasis that hydrogen fluoride and ammonium bifluoride are very dangerous chemicals, especially in any concentrated form. While using them in the diluted solutions I suggest, there could still be problems if a large amount gets on your skin. Wash the area with plenty of water and remove any clothing contaminated with the solution. Any alkali like sodium carbonate will neutralize the acid, but the resulting sodium fluoride is still dangerous for the skin. Having a solution of calcium chloride on hand would allow you to quickly neutralize any free fluoride molecules by forming calcium fluoride, a solid material, also known as feldspar. Calcium chloride can be purchased as crystals used to dehumidify wet areas, or as a replacement for common salt to keep driveways free of ice. Make up a solution and keep on hand just in case. If there are children coming into the studio, any dangerous chemical must be stored safely away from them. Certainly do not store any toxic material in containers previously used for beverages.

To help make the silicone bond better to this chemically eroded area, I have found that an application of dilute sodium metasilicate is helpful. There must be some fluoride molecules left in the grain of the aluminium which prevents proper adhesion of the silicone over time. Since metasilicate is alkaline, it reacts with any free hydrogen fluoride molecules; at the same time producing a layer of aluminium silicate for the silicone better to adhere to.

A stripping method using solvents

When using the smooth backs of plates, I have found a reasonable method of removing the silicone without the need of HF in much diluted form. While this procedure requires a hydrocarbon, turpentine or citrus thinner, it can remove enough silicone to allow a grit containing 3M pad to produce a reusable plate.

If you are reclaiming a number of plates, then I would moisten the surface of two plates and stack them face to face so that the solvent can start softening the silicone. A large number could be put together and wrapped in plastic for better efficiency. After a while, take a piece of steel wool or 3M pad and start scrubbing the surface. The silicone should peel off and produce a polished finish that you can see. Never let the solvent dry as the silicone can be rebonded to the metal. Wash the surface with a strong detergent to get rid of the water rejection, then flush with water. It might be advisable to use a stronger acid counteretch as well to make sure that no silicone is left bonded to the surface. This can be just plain phosphoric or hydrochloric and water without the need for the dangerous fluoride molecules. Apply sodium silicate or metasilicate with a pad and a green 3M pad to get the all-important layer of aluminium silicate onto the surface.

This method takes more care as any deposit of silicone left on the plate can be a problem. It is up to the printmaker to decide which of the two methods that works best for them. Both require the use of undesirable materials, but a well-ventilated area makes solvent use more acceptable. In my opinion, the use of very weak HF is the simpler and more effective method.

Washing out the image (development)

Wash out the toner with pure acetone, or a mixture with retarder - this is a developer. The developer mixture slows the evaporation of straight acetone and makes the washout easier. Because hydrocarbons will affect the silicone, they cannot be used to remove the toner image, so acetone is used to remove the plastic materials. While the retarder slows rapid evaporation and prevents the toner from rebonding to the silicone and image, it gives us time to dissolve the entire image before water is used for the final cleanup. In my recent search for a non-toxic retarder, I have found that polyalkylene glycol ether works quite well. It is present in many commercial products that are not listed as dangerous. All DOT 3 and 4 brake fluids contain 92-99% of the water soluble glycol. Only about 5% or less is needed to keep the dissolved toner wet until water can be used to clean the plate. Don't use the DOT 5 fluid as it is made up of silicone oil. In Europe I found they used a different material for brake fluid, which did not work. Another good retarder is propylene glycol available at drugstores. It is used in food such as salad dressing and would be safe also.

A retarder for a washout solution will save on materials and expose you to less acetone if that is a concern

Wash out the toner image with paper facial tissues by pouring the acetone developer first on the tissue. Use a small circular motion to soften the toner and remove the major portion. Do not attempt to completely clean that area of the plate but continue removing the greater part of the toner, especially thick areas. On the first attempt you will leave a thin veil of toner over the image area but this can be more carefully attacked later with fresh tissue. It may be necessary to apply acetone to the entire non-printing area of the plate to remove the thin layer of silicone oil that some silicone compounds might leave on the surface. This will depend on the brand of silicone you are using. If this silicone oil is not removed, the ink roller will pick it up, preventing proper transfer of ink to the image. 

As soon as all of the toner is dissolved, it is quickly washed off with water and a sponge - soapy water is not a bad idea either. This method reduces the amount of developer and acetone used as the retarder prevents the dissolved toner tint from drying too quickly on a plate. Without the retarder, one would have to constantly add more acetone to the plate; a bad idea if we want to be a safer printmaker. This technique can be used in most cases except when gum is used under the silicone when doing reversals, which requires pure acetone.

There is no need to apply vinyl lacquer or any other printing base. Where the silicone rubber has been removed from the metal surface, the plate will print as the ink comes in contact with the image area. After ink is left on the metal plate for any length of time, strong chemical bonds takes place which becomes the permanent printing base. If the image rejects ink because of residual silicone oil, just wash that area again with acetone and continue to roll up. In stubborn cases, I use ink picked up with a cloth containing acetone and rub this into the offending areas. Once the ink has taken hold, the plate will print perfectly.

Over the last decade, I have not had any rejection problems due to residual silicone oils in the applied film as the recent caulking silicone must have changed their formulations. I have never had problems with Dow-Corning or the new Japanese silicones sent me.

Converting proofed grease and photo plates

Grease images that have been proofed as gum/water images can be converted into the waterless process. Make sure that there is a good vinyl lacquer base under the grease image, reinforce it if in doubt. Remove all traces of ink with a suitable hydrocarbon; leaving the lacquer base.  Wash off the gum. After drying the surface, apply the silicone coating as before and cure. Remove the lacquer base with acetone developer and roll up with ink.

For those artists loving the looks of tusche washes, you can convert the plate for problem free printing of the edition

It is very easy to convert both negative and positive photo plates into waterless lithography. I have done this with a number of different products. One make of negative plates I encountered would not convert easily as the image could not be removed with acetone. By adding a very small amount of methylene dichloride to the acetone, I was able to make that brand of plate work as well. The procedure for all plates is to first remove all the gum with water, rinse and dry. In fact, thin gum film can be left on if multi-color editions are to be made from the one plate (discussed later).

After drying, apply the silicone rubber as if it was on a toner image. Upon curing, the image is removed with acetone, alcohol or the developer used for the positive plates, depending on the maker of photo plate. The positive plate developer will work if the image was exposed to enough UV to destroy the bond. The plate can be rolled up with ink as before. If the image is not completely removed to the bare metal, the plate should still work. As long as the silicone rubber is removed from the image, the remaining developed photosensitive material will take ink.

Processing photo plates directly as waterless

I have been able to process both negative wipe-on plates and positive photo plates directly as waterless. The acid gum etch supplied for these plates is not used as they would then have to be treated as a conversion. After exposure and plate development, the surface is rinsed with water and dried. Silicone rubber is applied and buffed down. After curing, the image is removed with acetone developer, methyl alcohol - or the plate developer, after giving a second exposure to destroy the positive emulsion. The diazo wipe-on negative image does not come out completely with acetone but the silicone rubber is stripped off, allowing ink to take hold. Fuji, DuPont and Hoescht positive plates worked so well that one would think they were designed by the manufacturer for this waterless process. In the last couple of years I have developed a way of coating recycled plates with diluted screen emulsion and processed into very good positive plates. The information is on this website.

Making reversals of any waterless image

Working with reversals in waterless lithography means you will have to decide on the procedure before you start. Image making materials cannot be water soluble as you will use Gum Arabic as a temporary base for the silicone coating if you wish to print the first color as a positive. While reversals in traditional lithography call for the removal of the gum layer so that the plate will accept ink, silicone cannot be removed with even the strongest acids or solvents without destroying the image. It is a simple matter to set up the processing to allow for the removal of the silicone coating.

The very first test of a waterless reverse by Alan Flint - even attempting to print as a positive first. CU detail shows retained toner wash

The image can only be done in toner or water resistant plastics such as Sharpie markers or Future floor polish for this method to work. After the toner is set and the plastic drawing ink has dried, a layer of thin Gum Arabic is applied over the entire surface that is to be reversed. Silicone is next applied over the dried gum and cured, the image then developed with acetone alone and printed as a positive if so desired. Water must be kept off the plate as it would remove the silicone coating.

If the plate is to be printed as a simple reverse without ever needing a positive image, then things become easier. After the gum is applied over the plastic image and dried, the image is removed with appropriate solvents. Now put silicone only into the image area and buff down to a nice film. After curing, the gum is washed off, taking the silicone with it, leaving only the image as the reverse. Borders have to be considered and can be put on with masking tape at the same time as the image was done. The tape would be removed with the image.

When a positive image is used, for the reversal to take place, the image is first washed with solvent to remove the ink. Make sure all the ink is removed by washing the image area with lacquer thinner if need be, as there is no fear of damaging the silicone, which is to be removed. Apply and cure silicone over the image area to be reversed. Now take a wet sponge and cover the entire plate and let it soak into the gum layer under the silicone. You may have to rub the surface with your fingers to help lift the silicone, but this is easy to do if the silicone layer is not too thick. After all silicone is removed, the plate can be printed when dry. Borders can be produced by applying masking tape before the gum is put on the plate, or they can be covered with silicone later.

When doing multicolor editions using this reverse technique, it is possible to save a portion of the image to overprint colors. If there are areas of the plate that are not to be reversed, they can be protected with orange shellac, which is applied like lacquer base. After applying silicone to the original image to be blinded and after washing the silicone off the surface with water, wood alcohol or acetone is used to remove the sealer and reveal the original protected image. No water must be present in these solvents as it could damage the original gum still beneath the silicone that was protected by the shellac.

Using this technique to print multiple editions from one plate

Our students have found that they can print many editions from one plate if they first undercoat the silicone with gum. Some have printed as many as eight editions or multicolor plates from just one surface. After printing their edition, they don't reverse the image; instead they wash or counter etch the plate lightly. This removes the silicone and gum at the same time. For multicolor editions, the remaining ghost image is helpful to lay down the next color. For a new edition, they disregard the old image like the ghost left on screens in screen printing.

While the use of water is restricted in this technique, I have found that the Omnichrom pencil can be washed out with acetone, making it possible to do crayon manner drawings. First cover the entire plate with gum. The drawing is done with a #108-9 Omnichrom pencil, toner washes using A type toner, toner chalks or other materials that do not require water in application. After curing the silicone, the image is developed with acetone, but water is not used to clean the plate. You would have to use pure acetone as any retarder prevents ink from taking to the image until it is completely evaporated. After printing the edition, water is used to strip the plate clean -- ready for another image. My only concern is that silicone does not bond as well to gum as it does to bare aluminium. This could limit the size of an edition, but it is more than adequate for the small editions required at schools.

During the fall of 1997, I have developed a method by which old used plate can be recycled in this waterless process. I have found that the back of the plates actually produce a better image and have taken to using that side for all my editions. I found that common commercial aluminium from a metal supplier can also be used effectively for waterless printing; these much thicker sheets can be reused many times to save money. Look for my paper on this process.

Flashing aluminium used in the construction industry is the same thickness as grained plates for fine art. It is much cheaper than purchasing grained plates that you don’t need the grain for any reason.

Other substratum

While aluminium plates do present one of the better surfaces for this process, I have been able to produce good prints from specially prepared paper plates. Paper plates are difficult to make and would be best manufactured with better control than I could achieve in my studio. While not all paper plates performed perfectly at this time, there seems to be enough success to keep me working in this area because of the cost saving for students.

While regular litho stones can be used in waterless, they have to be first coated with a waterglass solution to protect the surface from the acetic acid in the silicone caulking. Dilute the sodium silicate so that it would produce a good seal on the stone surface. Buff the waterglass with a cloth that is lint free to prevent hardened particles after it dries. The drawing is done on top of the isolation layer with any of the previously mentioned materials. The stone can be grained after the edition is finished. I have not tried it, but the new Japanese silicone seems to be acid free, so should work on limestone. Regraining would be necessary to reuse the litho stone.

Another interesting surface is the use of common plywood's. The surface is first sealed with shellac. If a solid image is wanted, it is drawn with water soluble materials. After the silicone is applied and cured, the wood can be carefully abraded to reveal the grain of the species. I have never tried to find the total number of prints the plate may produce, but it should be more than enough. Waterglass can also be used for sealing the plywood surface, just as with stone.

Ross Zirkles nude combination of waterless litho and woodcut. Dan Welden waterless on plate glass printed at Littleton studio.
Mylar is another material that can be printed from

Glass sheets are another candidate as drawing surfaces. The glass has to be 3/8th to ½ inch thick to prevent breakage. The surface is sandblasted or grained with a small levigator. The new orbital sanders are a promising tool to make the work easier. This technique has been perfected by Littleton Studios in North Carolina. Other printers have learned the method from them and are offering printing services to artists, using this method.

Acrylic sheets can be grained in the same way but can only be used with water-based drawing materials. Silicone does not adhere to acrylic as well as it does to other substrates, but is a material that would be very interesting to use. There is on the market a special silicone caulking made for the acrylic plastic sign industry, which should be effective for waterless litho, but I have not had the opportunity to get some for testing.

I have used frosted Mylar but feel there is no advantage other than tracing-like methods for registration of colors.

Printing and using a clean sub-plate

Method #1

To make the printing area cleaner, it is possible to produce a subplate covered with silicone that will reject ink. While I have used old aluminium plates at first, common Masonite is much better for the classroom. At first, it was obvious to have the subplate on the press bed, under the printing plate. Because metal plates in time will stretch in the middle under pressure of the scraper; where the smaller plates are placed, the edges of this metal subplate will curl in time and will not lay flat on the press bed. Masonite is flexible and does not have this problem. If you have the space, it is much better to establish a rollup island next to the ink slab and press. Take a piece of 1/4" Masonite and cut it slightly larger than your inking table near the press. Use Masonite that has pronounced grain on the back as this will become the upper surface and is necessary to hold the silicone which will be applied to make the subplate. Attach strips of wood around what will be the underside, to keep the subplate from moving while rolling up a plate.

Masonite (hardboard) can make a suitable subplate for classrooms. These were made for use at my workshops

Dilute silicone as if you were going to use it on a plate but use it to seal the Masonite. Let it cure. Next day use silicone straight out of the cartridge and put a heavy bead across one end. Using a wide putty knife, spread the silicone as evenly as possible over the entire surface. Work the material well into the groves of the texture for a proper bond. As the silicone picks up broken strand of wood fiber, it becomes contaminated; replace with fresh clean silicone and finish coating the surface. Do this in a well-ventilated area as the acetic acid released is not a pleasant odour - newer silicones might not have this problem.

As the surface will likely be very ridged, it has to be rolled smooth in some way. Take a brayer that is about 6 inches wide and cover the surface with contact vinyl plastic (MacTac); this will help in restoring the roller for normal use. Roll all over the surface and spread the silicone evenly as possible, but there will be an orange peel texture on the surface. Set the roller aside and remove the plastic only after the silicone has cured. The subplate surface can now be polished to a smooth finish with a cellulose sponge dampened with water. Let the subplate cure overnight and apply another coat next day or two until all fibers have been covered or eliminated. If your Masonite leaves fibers sticking up on the first coat, they can be singed off by passing the flame from a propane torch lightly over the surface. It is not necessary to have all the Masonite groves filled to produce a perfectly level surface. It is important that there are no high ridges on the surface as this will produce uneven inking of the image. With care the subplate will last a long time and can be replaced inexpensively or recoated if damaged in any way

When the silicone is well cured, it will produce a surface which will not take ink. When used, the actual printing plate can be attached to this subplate, allowing you to roll off the edge of the plate without leaving a layer of ink all around the printing plate. This makes for a cleaner area with less chance of soiling the print and certainly less messy at cleanup time. Since many of our students use registration pins, these are attached to the press bed, leaving the rolling up of the plate easier as the pins do not get in the way of the roller. This extra step in no way impedes printing.

Since a thick coat of silicone has a sticky feel, it will at first hold the smooth back side of the metal plate and allow you to roll up and print with no problem. One brand of silicone I used for this purpose held too well to the smooth back of the plate so that it was badly bent when I tried to remove it. I had to wipe down the back of subsequent plates with liquid soap to get the right stickiness. This problem goes away after a few plates are printed.

Some ink will leave a deposit on the subplate where the roller had stopped. After finishing printing, this should be removed before the ink dries and becomes harder to eliminate. I just use some acetone and facial tissue. After time and much misuse, the surface may lose its’ ability to reject ink – apply a fresh dilute coat of silicone.

Method #2

Another solution to make a subplate is to use two of your biggest aluminium plates and secure them to a table so that they leave an area around the biggest plate you use. By coating them with silicone, you get a smoother surface at the cost of two used plates. I have used old plates from finished editions which have had the image washed out and blinded with silicone. All damaged silicone surfaces can be fixed by removing ink with a strong solvent, then recoating the surface with silicone. The two plates can be fastened together at the back with thin commonly used packing tape. This would be necessary if you are using large plates for editions.


Method #3

Surplus plate glass that is grained makes the best subplates as they are smoother and easier to add silicone

For my own studio, a sheet of plate glass that has been grained and coated with the diluted silicone makes the best subplate of all, as it is perfectly flat. This is placed on a table next to the press. About once a year, I will clean the surface very well with solvent, and then apply a thin fresh layer of silicone. This is the best of all subplates that I have made and tried. I would recommend it for a working studio, but not for a classroom.

Flat surfaces

I remembered the number of ink slabs and subplates that I have run into at the various workshops over the years. Many of these were either hollow or raised in the middle just enough to not produce an even layer of ink when used with a harder durometer roller. Leather rollers have enough give to take uneven surfaces into account if not too severe, but good rubber rollers will not lay down a level film of ink on the plate in most cases. This becomes apparent when printing large areas of delicate smooth tints using any structure of dot patterns - like toner washes or laser halftone and inkjet photo plates.

My 45 durometer 3-part roller system will show up this snag when using a very thin film of ink required when printing with linear offset. Unlike traditional litho, using leather rollers with heavier inking, offset requires a thinner ink film to prevent dot gain due to squeeze from the rubber blanket, which produces darkening of the image. Flatness of the ink slab and subplate are therefore more important when using offset - especially with transparent ink.

I believe that most printers do not realize that even a 1/4 inch sheet of glass is flexible enough to show up any unevenness of the surface it is laying on. Today’s fiber optics proves this point as thin glass can be bent into considerable tight curves without damage. Getting your table completely flat under the glass slab is the first step of making a good ink up slab.

For more accurate rollup of plates, I have found that glass slabs and subplates can be uneven and must be leveled.
They can be shored up with cardboard and paper as was done on my subplate
.

What level of tolerance is necessary for good printing? The first problem is finding a long enough straight edge to be totally effective. If possible, go for the best, which would be the same as grinding the surface of a large litho stone - less than the thickness of a piece of writing paper - about .003 of an inch. The straight edge to meet this standard and could be expensive for one around 24 inches long. Those on the market will have accuracy of .001 over the entire 24" length for steel ones and .003 for aluminium. You have a choice on how much this is worth to you as steel is roughly twice as expensive. Nothing over 24" would be needed as most rollers are less than 18" wide. Use the same technique as leveling a stone when grinding it flat.

Inks best suited for waterless printing

The ink that is needed for waterless lithography has to be of high viscosity, non-greasy and with high tack to start with. Some black inks work very well just as they come from the can but other will need modifiers. Some require so many modifiers that it would be better to choose another ink for printing the edition. Because of the concern that commercial litho inks may not be permanent, my early work was done with inks accepted by the art community. I have now tested a number of available inks and have found Van Son rubber based to be near perfect. They have much stronger pigmentation than some other popular brands. My process works best with the new quick set inks that are common on the market. Inks that were satisfactory are:

*Van Son Rubber-base inks. These stiff high tack ink printed the best right from the can.

*Hanco CS series are made with quick set vehicles and will work quite well. These inks need more modifiers than Van Son. Can be mixed with Van Son.

These are the best ink to start waterless with. Van Son is much better than Hanco because of formulation

Sun Chemicals has developed an ink for the commercial waterless offset industry. Their first product is called DriLith and is much like other solvent inks. The new product that showed promise was DriLith W2, which was a water reducible type for the waterless presses. I have been able to get samples of both and while promising; they both have driers and are a problem for hand printing. Apparently the promise of waterless lithography completely taking over the commercial industry is premature. The available commercial plates are very expensive and they cannot fulfill extremely large orders as the silicone breaks down. This process will probably be reserved to expensive very high quality printing jobs.

Modifiers for inks for straight Van Son and some other inks

If there is uncontrolled tinting, the Van Son ink should be made shorter with the addition of epoxy hardener alone, the resin is not used. Magnesium carbonate is helpful in some inks. Take a very small amount of hardener and work it into a small amount of ink, then add more and more ink to incorporate the hardener into the ink. While most work, I have found regular Lepages epoxy was the best hardener for this purpose; do not use the 5 minute epoxies. If too much hardener has been added and the ink does not want to transfer, use one of the drying vegetable oils such as sunflower, safflower or walnut salad oil, as well as linseed oil. For a less viscous ink I use these drying oils as modifiers over flash oils and the like. I now modify some inks so that they practically pour off the spatula; this gives me greatest detail in the fine tints and keeps the darks from plugging up. I have also found that the new alkyd gel in a tube, used by painters, make a very good reducer. I like to print on soft smooth papers such as Arches 88 to get the most detail, when having direct plate to paper contact.

Most ink can be made to print with modifiers and patience.

The latest modifier I have developed consists of body gum and Venice Turpentine from a store dealing with horses. Making the modifier is elsewhere. I make up a small batch by adding epoxy hardener to it and saving that in a small can. It will skin so use a piece of the cover paper. A bit of this added to ink increases the tack and reduces tinting. I have produced much better tacky modifiers but their formulation gets too complicated and from what I know of printmakers, not likely to be used.

Rollers best for waterless

Good synthetic rubber rollers are the best to use. Leather rollers may deposit the ink more even and bring up the lightest tints on the first passes, but they leave tinting on the plate. Brisk rolling with a rubber roller will give you good results. If there is tinting along the edge of the plate, use a small diameter brayer and go over these area quickly to remove the ink. The brayer can be rejuvenated for the next pass by rolling over an old telephone book page or other paper.

A very slow roll with plenty of pressure may be required at first for the ink to stick, but a fast roll across the entire plate will lift the tinting. Do not stop or change direction in the middle of the plate because that will leave a tint line which may become hard to get rid of by rolling. While it is hard to over-ink, don't, as this process does not release the excess ink as quickly as flooding the plate with water in traditional lithography. Over-inking has to be removed with a sheet of newsprint run through the press. By using the smoother back of plates and newer silicones, this has not been as bad a problem as before.

Because of a very stiff ink and the thickness that results, darkening of the dark areas can be a problem. This does not fill-in permanently on the plate and the image there looks the same as before, but the pressure of the scraper has forced the ink to spread and darken the passage. Use a softer ink to produce the lightest tints and the cleanest dark passages. I have found those papers which are soft and can absorb ink under pressure, give the most accurate impressions. Calendared papers can produce very fine impressions when the pressure is adjusted properly.

It is much easier to print waterless with small diameter rollers that snap off the ink from the plate surface

I have developed a three part roller that overcomes 90+% of tinting problems. This roller assembly consists of two smaller diameter rubber rollers (1.5 inch) that contact the plate, with a larger (2.5 inch) metal supply roller the contacts both. The small diameter rollers provide greater snap because of the sharper angle of the roller to the plate surface. (Data at end of this paper)

Wash up solvents

In the past I used to remove ink from the image with acetone, when a change of color was needed. It depends on the binding vehicle used to grind the ink, but some inks can be removed with alcohol. While it may not take out the ink right to the bare metal, enough is removed to provide a clean printing plate. The residual ink within the grain of the metal act as a printing base; acetone acts the same way as alcohol with some inks. A mixture of the two is possible to nicely clean your particular brand of ink. Try a 1:1 mixture of acetone and alcohol. By modifying the commercial ink, you also change its solubility in alcohol or acetone. Some ink is never been bothered with it. The other advantage of the alcohol is in the way the ink is removed. By using facial tissue and a liberal amount of alcohol, a tight circular action will strip the ink from the surface as a gummy, tacky residue. By not dissolving the ink, less alcohol is needed to clean a plate. A few citrus type cleaners work well on some ink.

It depends on the makeup of the ink and modifiers that will affect the way ink is removed

While I have not been able to obtain Isopar, an iso-paraffin product from Esso, I hear it washes out a plate effectively, without damaging the silicone coating. It is used with commercial Toray plates. Various grades of Isopars are available but I do not know which works the best.

Adding more silicone rubber to the surface

If for some reason the ink starts to adhere to the plate, you may be able to recover the image and save the edition. There could be a number of reasons for the problem and understanding the process can help in determining the remedy. The surface of the plate may not have been clean enough for the silicone to take hold, and in time has started to strip off in the contaminated areas. If the plate has a very rough texture and your silicone not heavy enough to bridge the sharp points, this will also cause tinting. In each case it is possible to add fresh silicone, as long as there is some silicone still present on the surface of the plate.

If areas outside the image have not had enough silicone rubber or it has been damaged, those areas should first be cleaned with acetone, white gas or lacquer thinner to get rid of all the ink and clean the metal surface. Counter-etching is probably the best remedy but applying silicone rubber without counter-etching may also work. If I want to prevent problems, I will apply a weak solution of sodium metasilicate to the area first. Next apply silicone, buff the area and cure the rubber. If part of the image is to be deleted, the same procedure can be followed. Waterglass or sodium metasilicate produce a layer of aluminium silicate, a good base for the silicone. To hasten the drying of the silicone, I use a more diluted solution that is made up of camp stove fuel, which evaporates very fast. It can be applied in more than one application to build up a reasonable layer of silicone.

If you want to apply silicone rubber over the entire plate, you must protect the image from the silicone. What is needed is a material that will stick to the clean metal in the image and be rejected by the silicone coating. After the silicone rubber is applied and dried, the protecting layer can be removed to restore the image. For this we can make a special ink. First the ink must be removed from the image and made acceptable for a water based material. This is best done with acetone and a retarder, such as the toner developing solution. Washing the surface with strong detergent should improve adhesion of the water-based ink.

This mixture with different viscosities can be very useful for improving plates and even images using monoprinting techniques

My recent discovery is a perfect image protector for this problem. It consists of molasses (treacle), colorings and some retarders. The formula I have been using successfully consists of equal parts of molasses, Golden Acrylic Retarder and polyalkylene glycol (available as DOT 3 brake fluid). It is not toxic. You can add Prussian or Thalo blue dry pigment for colorings, or a strong water soluble dye such as methylene blue. Do not use carbon black as there is enough affinity between it and silicone to produce a problem. Rollout some of this solution on a slab with a brayer and go over the image area until a decent film covers all. At first the ink will take to the silicone, but as you roll, the ink becomes stiffer and tackier, then starts to be rejected from the surface of the silicone. Because of the retarder, it is possible to get even inking over the entire surface. Keep rolling until the silicone is nearly free of ink. I have found that the heat gun set on low heat will let you control the drying while rolling. Since the ink will be still sticky, force air dry it with a heat gun until it doesn't come off on your finger. Now use a Kleenex saturated with odourless paint thinner and remove any unwanted ink that has stuck to the silicone surface. Use water to clean any places that are to be deleted. If for any reason you did not roll the image evenly, spray the surface with water from a finger pump and start over. After the image is dry, silicone can be applied. Any ink sticking to the background should come off with the odourless solvent and a little rubbing. You can modify this molasses solution with other materials such as magnesium carbonate or more retarders like glycerin. While honey and syrup can work as a water soluble mask, I have found molasses the best.

Making quick corrections to areas picking up ink

There will be times that for some unknown reason an area of the plate may start to take ink. If these are cleaned with white gas, the surface will be dry in a moment and can be resurfaced with silicone. I think that it is a good idea to apply some sodium silicate until it takes to the surface, then flush with clean water and dry. Prepare some caulking silicone diluted with pure white gas or lacquer thinner rather than odourless thinner, to produce a fast drying solution. Dilute the silicone much more than for surfacing the plate and store in a tightly closing bottle; I keep mine in the freezer. Apply the deletion fluid with a Q-tip for tight areas, or a facial tissue in the open sections. Buff quickly to an even film and allow drying for a little while, or forcing dry with the heat gun. In most cases this will blind the offending area and you can proceed to print the rest of the edition. If they are available to you, Toray has vials of a blue fast curing silicone that have their own brush-like applicator. These are quite expensive and have a very limited shelf life before opening - and even less after.

Putting the plate away and cleaning up

When you are finished printing or proofing, it is not desirable to wash the ink from the plate. On a number of plates where I removed the ink before storage, the silicone seems to have crept into the fine image areas and blinding the fine dots - prevented reprinting of the plates. I feel that the ink protected the metal surface from oxidization and could be removed later with acetone, if it hardens. The best new method I have found is to remove the ink with acetone and apply a thin layer of the image protector made from molasses, retarders and colorings. Do not worry about any protector covering the silicone background. The non-printing area covered by silicone retains its rejection capability if not damaged in any way. If you make sure that the image is first washed with soap so that water soluble glues solutions will stick, then just apply gum or other material with a cloth.

I once protect the stacked plate between 6 mil polyethylene plastic. This is available in rolls from the local builder supply who sell it for a vapour barrier. Another handy tip is hanging plates from long pins spaced to fit into the registration pin holes. I have four sets of these on the door to my darkroom next to my presses.

Replacement for grease on your tympan

To do away with the constant refreshing of common grease on the tympan after each print, I have found that the wax used to make the connection between the toilet and sewer lines - a perfect replacement. It can be quite stiff, so look for a product that is soft enough to spread. A better substance is made by melting the wax and adding some STP motor additive to make it less viscous; not much is needed. Use a wide putty knife to lay a bead in front of the scraper bar, then a few more over the entire tympan surface. Run the press bed though once to spread the wax, then remove the excess with the knife and put it back into your supply. This very thin coating of wax is more effective than grease and does not have to be refreshed with each print. You can tell if there is still wax on the surface by running your finger across the tympan and see if that leaves an impression when seen through reflected light.

Replacement of leather scrapers

Expensive scraper bar leather can be replaced with polyethylene underground sprinkler hose. This is cut is half and stretched by means of pliers to get a tight fit. The waxes in the plastic give some slippage, but with the above wax, it functions better than leather. It will outlast leather in most cases, but is inexpensively replaced when damaged.

A couple of methods to stretch the hose unto the scraper bar. It is best to round the sharp edge of pliers where they pull on plastic.
Use mix of STP and toilet bowl wax instead of grease on tympan

Observations

Waterless lithography is very different than traditional gum/water printing. Less chemistry is required as only a few store bought materials are needed. There is no real need for hard-to-get products such as Gum Arabic, the various acids one must use, the soft cheesecloth or lintless wipes. All the materials I have used are available in town as household or everyday trade products. None are toxic to any extent, and are inexpensive besides. The main advantages over gum plates are:

1/ If toner or water-based materials alone are used for the image, there is no need for vinyl lacquer base with its toxic solvents and strong odour.

2/ Acids are only needed for counter etching and then other commercial products can be very easily obtained.

3/ Timing of the application of etch is not required to produce a stable plate. Things like over or under etching is not a problem.

4/ Because the carboxyl radical is present only in the ink, while the non-printing areas are covered with silicone, a more stable plate is the result. Blinding or filling in is not a problem.

5/ The silicone rubber layer is tough enough and bonds very well to proper substrata.

6/ Stopping to print for any length of time does not require the plate to be gummed up and later washed. Putting the plate away for later editioning requires no special consideration. Depending on the ink, the plate can be left for a number of days before finishing the edition.

7/ I have found the plates to take considerable abuse before problems arise. This happens mainly because I try to find the limits to the process and subjected the plates to a variety of materials that would normally not be used. The new Japanese silicone has done away with many minor problems I encountered.

8/ In traditional lithography, when printing color editions, wet ink may sometimes offsets to the non-printing wet areas of the subsequent plate and takes hold. Silicone rejects the ink, preventing this problem. Multiple colors can be printed in one day.

9/ I have found that the lightest tints can be better reproduced with the waterless process rather than gum/water plates. Because there is no acid to erode the image, the light tints remain on the plate.

10/ Hot air from a paint-stripping gun can be used to quickly dry and cure the various materials used.

11/ Because the process is waterless, the paper stays dry and dimensionally stable. Paper registration is more assured and colors tend to print clean and brighter.

Disadvantages

1/ As in most cases, improvements are not without some sacrifice and this process is no exception. While the technique has problems, they are of a different nature than gum/water lithography and have to be overcome. The most important concern is the loss of making changes to the plate; by adding or changing the character of the image. Because the silicone layer holds so tenaciously to the metal, it is very difficult to remove the materials to desensitise an area for changes. The use of a weak ammonium bifluoride solution may be less desirable, but it is a very effective stripping agent.

2/ Buffing down of the silicone rubber has to be very smooth so that lines do not appear during printing. The final buffed film need to be no thicker that 3-4 microns, the same amount that commercial Toray plates have.

3/ The need to use acetone instead of a cheaper hydrocarbon such as Varsol can make wash out more expensive. If you are accustomed to use commercial lithotine, then the cost is about the same or less. Acetone with other additives removes ink in a peculiar way by not dissolving it, but by lifting it very clean off the surface.

4/ As in most cases, when a plate losses an image, there is not much that can be done to bring it back. While more forgiving than traditional lithography, the plate can become unprintable if one is careless with processing or use of solvents. As long as the silicone rubber layer is intact, the plate should be able to be brought back to a serviceable state.

Conclusions

Waterless lithography has been a dream of some commercial offset printers as they saw advantages to get rid of the fountain solution that used chromates or isopropyl alcohol. The ink water balance is a factor, which makes the difference between an excellent print and one that is just passable. Humidity and other factors make printing of traditional lithography as much an art as it is a craft, with the printer bringing his or her experience into the editioning. A stable plate is the goal of the printer and any technique that provides it should be accepted by the profession.

I have been asked, if a water plate is printing well, why convert it to a waterless one? If the printer is skilled enough to produce perfect plates every time, then there is no need for change. But it takes many years of experience to become a master printer who can control all nature of lithographic techniques. I have found in waterless lithography, there is more forgiveness and so editioning can be much less of a problem. I have encountered traditional printers from stone, on their first experience with waterless lithography on plate, to be very animated at the discovery of how simple it is and what it can do. Only time can tell if this process will have any effect on the printing of fine art editions.

I developed the basic process in June 1990 without the input of anyone else and have been improving it since. It is capable of printing large editions as has been proven by other printers. I am wholly responsible for this process, which has become the basis of techniques promoted by others. It is unrelated to the commercial Toray process that uses photo negatives or positives. I have invented the 3-part roller that makes waterless litho much easier to print. That piece of equipment was once manufactured by others; there was even an attempt by them at patenting the innovation.

Glossary

· Acetic acid: An organic acid found in vinegar. A stronger form is released by the silicone rubber on curing. Because of the small amount released when used on a plate, there is little health risk involved.

· Acetone: A ketone that is used as a strong solvent. It is more dangerous because of its low flash point rather than inhalation, which allow 1,000 ppm. It has somewhat the same effect on the body as ethyl alcohol, which is the main ingredient of common alcoholic drinks. It mixes with water and most solvents. Available from hardware and paint stores.

· Ammonium bifluoride: A compound containing ammonium fluoride with an added hydrogen fluoride molecule. Because of the fluoride present, great care should be taken in handling this material.

· Isopropyl Alcohol: An industrial alcohol used by the commercial printing industry in fountain solutions. Also used as rubbing alcohol. Toxic level is 400 ppm.

· Lithotine: A turpentine substitute consisting of aliphatic hydrocarbons, pine oil and gum ester and/or castor oil. Because of some of the hydrocarbons, the toxic level is 100 ppm.

· Methylene chloride: A low boiling point chlorinated hydrocarbon. Avoid prolonged exposure to vapour. Used in the screen printing industry.

· Odourless Paint Thinner: A hydrocarbon that has been refined to remove the smell of solvent by eliminating the 15 % that were the aromatic compounds. This changes the liquid so that is has less of an effect on the silicone rubber and some toner images, than one gets from ordinary paint thinners. Toxic level should be slightly lower than paint thinner, probably around 450 ppm.

· Silicon: The 14th element on the periodic table, it comprises 25.7% of the earth's crust and the second most abundant element in the universe. Never found free in nature, it can be combined to form many different types of materials.

· Silicone: Silicones are important products of silicon. Technology can produce polymeric products that range from liquids to glass-like solids. Caulking compounds are rubber like materials that are useful in the waterless process. Available in hardware and paint stores.

· Barstool: A high flash point hydrocarbon originally known as Stoddard solution.

· Stoddard solvent. Its toxicity level is given as 100-400 ppm. Sold as a paint thinner and cleaning solvent, it has a number of other uses.

· Vinyl Printing Base: This product will vary from one manufacturer to another but they all seem to contain aromatic hydrocarbons and ketones as solvents for the vinyl plastic. Considered a health hazard.

· White Gas: An aliphatic hydrocarbon with a very low flash point. Sold as camp stove fuel in sporting stores and hardware's. Known in the USA as Coleman Fuel

 

Materials List and Formula for Various Solutions Used in This Waterless Process
           - that are not available in a normal lithograph workshop

Drawing materials

* Staedtler Omnichrom 108-9 pencil- a black water soluble pencil unaffected by hydrocarbons. Sold in drafting supplies and some art stores. Used for crayon drawing effects.

* Sumi ink - An inexpensive black ink from the Orient. Can be modified with dextrin, sugar or other water soluble glues to make it impervious to the silicone. Used for pen lines or solid flats.

* Toner - Dry copier toner washes used for reticulated textures -- using both water and solvent washes. Compressed toner can give charcoal effects. See my toner paper. Today's toner contains black iron oxide instead of lampblack, making it practically non-toxic.

* Future drawing fluid -- Common Future Acrylic Floor Polish, diluted with water and coloured with Sumi ink or colorant, makes a waterproof image. Used for pen lines and solid flats where water-soluble materials cannot be used, such as reversals.

* Various waterbased drawing pencils - Many of these pencils produce good images if they are heated after being used on the plate. I would do a test plate of all the pencils available to you.

* Ball point pens - Fresh ball point pens make nice fine lines but can be hard to see against the smooth metal surface. They have to be heated as well so they bond to the plate. They give better lines on the smooth backs of plates.

Setting Fluid

· White gas -- Common camp stove fuel from sport supplier is used to set toner images sometimes. If type A toners are used, the white gas is used as a carrier by adding 5-10% acetone to help bond the toner to the plate. Test the amount of acetone solvent needed for your toner. Some toners require a slightly longer exposure to the solvent, so the addition of common paint thinner will slow the evaporation and produce adhesion.

Silicone coating

· Caulking silicone -- Common clear caulking silicone in a cartridge is diluted with odourless paint thinner to the consistency of a light maple syrup. This is done in a small 4 oz. baby food jar. Add solvent a little at a time until the right consistency – 3:7 silicone:solvent. Dow-Corning clear caulking silicone is the best I have found, but seems to be no longer available. Instead, I have been using their # 999A or Trademate, a professional product that is available through Canadian contractors building suppliers.

Wash out solution (Developer)

· Acetone -- Common acetone is used to wash out toner and Future polish images. To retard the evaporation of acetone, Polyalkylene Glycol Ether sold as DOT 3 or 4 brake fluid added 5% in acetone make a good retarder that is non-toxic. Propylene glycol is another good retarder;  used in food products as well.

Ink Stripper

· Acetone/alcohol -- a 1:1 mixture of the solvents lifts ink without dissolving it. This takes less of the solution to clean a plate for changing colors. While it may seem slower than dissolving the ink with solvents or straight acetone, it is very effective and safe. Modified inks may need a different proportion of each solvent. Other additive may be used as well. Use Kleenex or paper towel for ink removal.

Soapy water -- When using DS/VS ink mixture, plain soap and water will remove the ink from the plate.

PineSol Mixture -- A solution made up of PineSol, solvent and Palmolive traditional dishwashing detergent will take off not only water-soluble ink, but plain oil ink very effectively. VCA can be used instead of solvent in this mixture.

Commercial degreasers -- Many commercial products remove oil and grease because of the surfactant being used in the solution.  These would be less toxic than pure hydrocarbon solutions.

Image Protector

· A mixture of molasses, colorings and retarders. This is rolled on with a small brayer.

Silicone Stripper

· Ammonium bifluoride -- Also known as ammonium hydrogen fluoride. Because it contains hydrofluoric acid in the compound, a weak solution of this will strip the thin silicone layer effectively. Place a pinch of the chemical in a plastic container and about 8 ounces of water to dissolve it. Add some phosphoric acid to improve chemical action. Next, add a strong liquid dye and stir. Alcohol or acetone can be added as a wetting agent if the stripper is not to be used on inked images; leave these out if it is to be used over images. If ammonium bifluoride is not available, use ammonium fluoride to which a bit of acid can be added to activate the stripper. Ammonium bifluoride is used by stained glass workers to etch glass and should be available from them, rather than a chemical supplier. Use these chemicals with great caution.

Odourless Paint Thinner

· Odourless thinners are sold in art stores as well as most paint and hardware stores. Use the cheaper paint store variety, but some will not work as they can harm your plate. Remember that it is still a hydrocarbon and should be used with care.

Silicone Caulking

· Dow-Corning clear silicone caulking in cartridges is the best material to use. In the small amounts used, the acetic acid used in manufacture is of little concern. With the disappearance of the Dow-Corning consumer material, other suppliers will have to be used. Ask for DC 999-A at a Canadian building contractors supply house. General Electric Silicone II is a good material for caulking windows, but rather a poor silicone for this process as I have found. Japanese silicone seems much better than those I have been able to buy locally.

Dry Copier Toners

· Toners can be of various manufacture and should be tested to learn of their characteristics.

· Some toners are not effected by hydrocarbons (type A), while the greater majority are (type B). Since these designations are my own for classifying the materials you may encounter, you will have to test the toner for yourself. All toner are usable, only that you will have to know their limitations. You should be able to pick up discarded toners from a laser cartridge refurbisher or a copy centre. Toner is basically plastics, the amount of acrylic, styrenes or other polymers is the manufacturers secret. See my toner paper for more information.

Applicators

· Soft urethane sponges are the best to spread the silicone over the plate surface. They should be cut into small 1.5 inch squares. A much larger one is used to back the facial tissue used to buff the silicone to a tight film. Common facial tissue is the best and cheapest to this purpose. The foam sponge material can be purchased from a department store where it is sold for upholstery. You should be able to obtain scraps from an upholstery workshop. Old pillows and mattresses are a good source.

POINTS TO REMEMBER

1/ Silicone caulking products may change without notice. While most work, the change may be enough to cause problems. I have used many brands but clearly found Dow-Corning better than most found in North America. It may be also marketed under others labels. Most cartridges today have a screw on tip, which only has to be filled with a bit of silicone by pushing in with the caulking gun. Don't cut off the tip as that will allow curing of the entire tube. Keep the silicone in your freezer for a longer shelf life, as it deteriorates in time.

2/ Make sure the tops of the aluminium grain is covered by silicone rubber, or tinting can be a problem. If coarse plates are used, two or more thin coats may be needed. For the finest tints, use the smoothest grained plates you can acquire or use the backs of plates. A slightly grained surface is better than a glass smooth surface to bond the silicone to the metal. The slightly roughened back of plates make the best substrates for this process.

3/ Hydrocarbons harm the silicone coating and allow the ink to stick to the plate. Acetone and alcohol's are better to remove the ink.

4/ There is no need for a vinyl printing base as the metal will absorb the ink molecules in time. While in gum/water lithography the strongest part of the plate is in the vinyl base and grease image, in waterless the opposite is true. Because the silicone bonds so well to the metal surface, it cannot be displaced, as a solid, it cannot move into the image areas.

5/ There are 3 possible ways to use this process:

I- Directly with a toner or water based imaging materials.

II- Directly as a grease image or conversion of a proofed traditional grease plate.

III- Directly as a photo image or conversion of a proofed photo plate.

6/ It is extremely hard to lose an image. As long as a thin layer of silicone is present on the metal, an ink-rejecting surface can be produced with more silicone rubber if the image is protected with molasses or gum.

7/ An effective drawing ink can be made from Future Acrylic Floor polish by adding a colouring agent such as lampblack in cheap Sumi ink. This fluid can be used also with brushes to cover large solid printing areas. Since only a thin layer is needed to protect the plate surface, it can be diluted to just the right consistency. Acetone can be used for development.

A simpler glue based ink can be made with dextrin or other glues, and Sumi or dye for colorings. The advantage is that it can be developed with plain water.

8/ White lines and other changes can be scratched into solid areas, just like in stone work. The silicone will protect the scratched area from taking ink.

BIBLIOGRAPHY

Semenoff, Nik. "Superior Tusche Washes" LEONARDO, Volume 20, Number 1, 1987, pp 71-77.

Semenoff, Nik. "A Lithographer's Notebook", Saskatoon: Semenoff, 1989.

Semenoff, Nik. "Waterless Lithography Using Traditional Grained or Commercial Photosensitive Plates", LEONARDO, Vol. 26, No. 4, pp. 303-308, 1993

Three Part Roller for Waterless Lithography

Developed by Nik Semenoff during 1992 & 93

Here are pictures of the three part roller that I have developed to make waterless lithography even easier to print. I was going to patent the roller but had decided to just make the design available to all printmakers. This roller is made from nitrile rubber rollers that have been ground down to 1.5 inches in diameter. The steel tube that acts as a supply roller is made of DOM steel .125 inches in thickness, 2.5 inches in diameter and 15 inches long. These are not important dimensions as other prototypes have been quite different and all have worked.

The support assembly is made from wood with one end block left free for taking it apart. The end blocks are made together so that the holes line up perfectly. The center support is made from two pieces of opposing wood grain that is grooved in the middle before they are glued together. While this roller has had the support lathed to close tolerances, other prototypes used planed supports. Plane the centre support until it is nearly a cylinder and cut to length, making sure the ends are square. Leave about .125 inches clearance between the steel roller and the end blocks by making the inner support a bit longer. A threaded rod is used to hold the unit together with the nuts at both ends secured with epoxy to the wooden handles. A third nut can be  used to keep the main assembly together when the rollers are taken out for cleaning. This nut is recessed into the end of the support so that the removable end block fits nicely. Glue can be used to secure these two pieces. In the ones I manufacture, the end blocks are not glued to the inner support.

To make the end blocks, measure the diameter of the rubber and steel rollers you intend on using. With a compass, draw the inside and outside diameters of the steel roller on a piece of bond paper. With the compass set to the diameter of the smaller rollers, draw a circle touching the larger one. Space the next small roller far enough apart to give the unit some stability. Next, draw the diameter of the end shafts of the small rollers. Indicate the surface of the plate by drawing a line touching the bottom of the smaller rollers. Leaving between .125 and .25 inch between the shaft and the edge of what will be the bottom of the end block, draw a line parallel to the plate surface. This space may vary with the diameter of your rubber rollers. This line will become an important line of reference later. Now complete the outside outline of the end blocks. This design has square ends that allow me to put the roller upside down for storage. The wide is bigger than the diameter of the metal steel roller but narrow enough to have the rubber rollers protrude a bit front and back. The four ends are rounded to and all edges are rounded as well to produce a charming appearance. Use a hardwood as it will become the bearings for the rubber roller shafts.

The diameter of the inner support is slightly less than the inside diameter of the steel roller, but placed in such a way that the all rollers are in contact when rolling up, yet lets the steel roller fall away from the rubber ones during storage. This prevents flat spots on the rubber rollers. To get the proper placement, draw in the diameter of the support so that it allows for some room (about 1/16th inch) around the top and bottom of the inside steel tube. This means the wooden support will be about 1/8th less in diameter than the inside of the steel tube.  The centre of the wooden support is the placement for the handled, where holes in the end blocks will be drilled. This is usually right on the centre point or just a little above. This hole will become the placement of the handles. Don't make the centre support too small or you will have a weak system.

From this template, transpose the centre points of the places where the hole will be drilled, to one of the pieces of hardwood for your end blocks, taking care that the reference bottom line is along one end of the long grain of the wood. Clamp the two small pieces of hard wood together with the bottom edges sitting on a flat surface, and then drill the three holes with the appropriate size drills. The holes for the rollers should not be too tight. Once the two end blocks are drilled, the clamps are removed. By using hardwood, it should hold up to the pressure and slow revolutions of the rubber rollers and bearings are really not necessary.

By leaving one handle removable for serious cleaning and assembling, the other end can be permanently glued or tightened with a recessed nut. In practice, I have found that the handle on this stable end usually can be tightened well enough to keep the unit together.

Before assembling the units, seal the surfaces with lacquer. Put the rollers in their place and fit the free end block to the main unit. Before tightening the free end block with the screw-on-handle, place the roller on your ink slab to make sure the small rollers are flat on the surface -- then tighten the handles. If properly made, the roller moves freely as the steel roller revolves on top of the rubber ones by pressure from gravity. When the assembly is turned upside down, the steel roller should separate cleanly from the others. The other nice thing about this roller is that you will never get blisters again, and it works perfectly for traditional lithography!

To keep down the amount of ink that would collect when the roller is put upside down on the inked slab while you run the plate through the press, I suggest to put domed carpet tacks at four corners to keep ink to the minimum.  For better control of the roller, I suggest you put your thumbs on top of the end blocks as this roller does not turn within your hands. No more blisters like printers could have.

The reason for this design is that the smaller rollers contacting the plate will lift the ink tints off the surface because of the greater upward lift or snap for any given forward or backward speed. Larger rollers have a lesser angle when orientated to the plate surface and not as fast a snap. The total circumference of all three rollers turns out to be greater than for the average rubber roller, so has enough ink to cover much more of a plate. Inking is also more even because the pattern is not repeated with the different diameter rollers. I have produced one model with different size rubber rollers to make the pattern even more ambiguous. I don't think there is enough difference to promote it other than you could easily use different size rollers if that was available to you.

Cleaning is very simple. Just add cleaning fluid to the scraped ink slab and pass the roller back and forth until the ink is dissolved. Then pass the roller over newspapers to get the rest of the ink off. If the ink from the newspaper dirties the rollers, clean newsprint can be used, or blanket wash will leave the surface clean for the next ink. The ability to take apart the unit is just to give it a very good cleaning every so often. If using PineSol modified water soluble cleaner, see my paper on water soluble ink.

I see no reason to use any other material than wood for making the support unit. Wood bearing have been used in the past with great success and should last for years if not abused. Wood is light and easy to work with, keeping cost down. For my manufactured systems, I have used soft metal sleeves or plastic tubing as bearings . Rollers may be more of a problem. I found old wringer washing machine rollers very good except for their shorter length. Since they may be old and not in good shape, most of the outer portions will be ground off on a lathe to reveal a fresh inner surface. I have also used inking rollers from a Multilith #1250 machine. These are 11 inch long and much smaller in diameter than I would like. There are two reciprocating rollers about 2 3/4 inches in diameter on each machine that can be used in place of the steel tube. These rollers can be taken apart to reveal a nice metal tube that is coated with rubber. These rollers should be available from discarded machines.

My very first attempt (in 1992) to build a prototype used rollers from a surplus supply. After careful construction and assembly, I was dismayed to find that these rollers were made of high silicone content as ink would not take to them! By temporarily covering them with MacTac, I proved the concept and started looking for pure rubber rollers. The designs progressed and I decided in 1993 on the simpler inner support system. I have commercially produce rollers 15 inches long, made from LHB (HT) Nitrile to meet requests by printmakers for a good working system. I gained a lot of experience in producing the 12 prototypes while doing my research and know just where close or loose tolerances are required. Good luck and I hope your rollers works as well as mine. The pictures of the roller are of the system I manufactured for sale, but if you have good construction skills and have access to lathes etc., then maybe you can produce a roller that will meet your needs. If you need more information on making your roller, feel free to contact me.

Today I have turned over the construction of the roller to:
Conrad Machine Company
1525 S. Warner
Whitehall, MI 49461
Ph# 231-893-7455
Fx# 231-893-0889

 

Recent Developments – the linear offset

In the spring of 1996, I produced a system that allows me to print my editions as offset by using my hand transfer press. I call the system linear offset because the motion is on a flat plane rather than using any a cylinder to hold the blanket. I have found the following many advantages to this method:

· Much less pressure is required for printing even the hardest and more textured rag papers.

· There are no salt and pepper areas because the soft blanket deposits ink in the hollows.

· Flats are always flawless and even in color.

· Registration is perfect.

· Colours are rich and bright even with one pass through the press because a sufficient amount of ink can be transferred from the plate and to the blanket, then to the paper.

The blanket can be flipped over for easier cleaning. The separate bed return motor system is rather complicated as it was added later



Linear offset used at the university workshop

I now print all editions with this linear offset attachment. It is easy to remove by the way it is secured to the present press bed; this allows for ordinary transfer printing. A Lexan tympan is hinged to a ¼ inch aluminium plate in a way to make removal easy for cleaning. An offset blanket is bonded to the tympan and all is kept in registration by the precision hinges and tapered registration pins placed at the foot of the aluminium plate. With this four-point registration system, perfect color registration is assured. Considering I ink up my plates on a subplate that is close to the press, printing is a continuous process. I ink up my plate while the sheet of paper is being printed; no time is lost. Since I started to use the system, I have lost less paper in an edition due to variation of color or insufficient inking.

Here are some quick sketches of the linear offset system.

 

Permission to photocopy this document is given to help get dangerous material out of our studios. Publication without the consent of the author is prohibited as I would want the latest information published. Contact me for publication.

Nik Semenoff D. Litt, Artist-in-Residence
Department of Art and Art History
University of Saskatchewan
Saskatoon, Saskatchewan
 Canada. S7N 0W0

e-mail address <nik.semenoff@usask.ca>

web page: http://homepage.usask.ca/~nis715

Blogsite: http://www.ndiprintmaking.ca/

Updated March 2014