ADDING TACK AND BODY TO YOUR INK

 

Tackiness in ink helps preventing tinting, the biggest problem with ink in waterless lithography. In my very early research into waterless litho I published the use of Venice turpentine to increase tack.  Since Venice turpentine is considered to be expensive and hard to find, damar varnish is an alternative.  While Venice turpentine is very slow in drying, damar dries too fast for printing. I have experimented mixing them with litho “body gum”; it is very viscous already and has very little greasiness, which we don’t want in our ink. While regular epoxy hardeners are of a great help, I have found that the stickiness of Venice turpentine works very well and more in line with ink binding medium.

 

I have found great differences in viscosity of body gums.  Made by the same manufacturer, batches years apart have no resemblance to one another. My early experience displayed an opaque yellowish very thick material with little tack. A can produced in 1996 was clear and not as thick. It was much too loose, more like lower numbered varnishes and very long in drying. This is the one I used in my tack mixture because I had not opened the later can I bought as a back up.  A can made in 2000 is about the right consistency for adding body and tack to some ink.


		

Venice Turpentine sold for horses hoves seems to be the same as the artists material I used for making glazing medium in oil painting. The are white nodules at the bottom of a can that has been sitting around for a long time and has to be heated to intergrate the material back into solution.


		

The price of Venice turpentine from art stores can be exorbitant so making this modifier seemed out of the question.  After much effort I was able to find Venice turpentine from an outlet dealing with horses.  Just like my art Venice turpentine, it had white crystal at the bottom that had to be heated and mixed into the rest. On cooling, the liquid had much more viscosity. The crystals must be the resin that remains after the volatile component evaporates.  I cannot see any difference in the two materials and have not been able to find any literature on this question.  On my last inquiry over the internet, I found many art stores now selling Venice turpentine at a very reasonable price compared to some other art stores. 

 

If you cannot get Venice turpentine then the first hurdle is to dissolve the damar lumps in turpentine as they are not affected by hydrocarbons. You may try citrus thinner, known a d’lemolene, but it is expensive and hard to find in pure form.  It has an orange scent and is less obnoxious than turpentine for some.  Suspend the damar lumps in the solvent by putting them in a piece of cheesecloth first. As the material dissolves, it will flow from the base of the wrapping and sink to the bottom of the vessel. Particles of bark will stay in the cheesecloth.


		
Diluted damar varnish is being thickened by allowing the common turpentine to evaporate in an opened container. Stir it every time you go by to speed the evaporation process. By adding body gum, the thick modifier will not dry too fast on the slab to make a decent tacky modifier. Venice turpentine is a wonderful addition if you only have very little of it.

 

You need to get a very viscous solution, so it is best to dissolve the damar and later evaporate the turpentine. I used about two time the volume of the damar with one of turpentine and left it for a couple of days, covered with plastic to prevent evaporation at this point.  After removing the cheesecloth, I did add about 10% Venice turpentine to the volume of the damar; but I have plenty of it from my early oil painting days.  Then I added some body gum and stirred it in.

 

Heat can be used to melt the damar lumps into hot varnish.  This might depend on the amount of debris in the crystals as these will come up in light colors as dark specks. An ordinary hot plate with good heat control is fine for heating the varnish to a high enough temperature to incorporate the damar.  First crush the crystals into a fine powder as this speeds up the melting and merger of the two medium. After the varnish is hot, sprinkle small amounts of damar on top as you stir the liquid.  Make sure no clumps form as these will take a longer time to integrate. Much will depend on the varnish used, but the finished cold mixture should be stiff enough to not spread out on the ink slab.

 

This is just Venice Turpentine and body gum that has been heated to thoroughly mix the two materials. When it cools, it will be very thick and tacky, making it a perfect modifier for most inks. Just a touch is needed to reduce any tinting taking place on the plate. It also retards drying of ink on the paper, helping you if you happen to be using ink with commercial driers. The heater is a 200 Watt unit meant to attach it to a motor block in cold weather by the magnet within it. A very handy and safe way to heat small amounts of liquids.

It is difficult to give the exact proportions as I adjusted my solution as I tried to work out a good thick tacky mixture. After I felt the proportions might be about right, I poured the mix into a bowl with a large surface to allow the turpentine to evaporate. I stirred the mix every time I passed by and allowed it to get much thicker than honey.  This was put into a container and I use it to increase tack on problem inks. It works very well when added to reds, oranges and yellows.  These are prone to tint and by adding a small amount of the Venice turpentine, damar mixture, plus some epoxy hardener, I have better control of the ink.  I can add more body gum or Venice turpentine to get the right results. I have found that epoxy hardener reacts with the mixture to produce very viscous and tacky additive but I prefer to use them separately as I incorporate the modifier into ink.

 

This shows that materials are not always the same from batch to batch so I have only given you the principals of how to make tacky modifiers. With the four compounds you should be able to make your own tacky modifier for easier editioning. A small batch should last you for a long time.

 

Published February, 2006