Art Articles & Reviews

} Waterless lithography: waterbased images Printmaking Series - Part 12 of 21 By Nik Semenoff In traditional grease/water lithography, the use of water has been a problem to the commercial printing industry. Known as the fountain solution, it contained other chemicals to ensure the best balance of grease and water to produce best quality work. On the chemical level, both the grease and gum bonded to the surface used the same carboxyl radicals; this meant that any change to the chemistry on the surface could allow either to move into the others area. This meant the image might disappear or the image darkens to make the plate useless. What was needed was completely different chemical bonds to separate ink and rejecting background. If water could be eliminated, so much the better. Toray, a Japanese company producing printing materials, finally developed a commercial plate that used silicone for the ink rejecting surface. The cost and availability of these plates are beyond the reach of most printmakers and were only occasionally used by them. In 1990 I started research into a less prohibitive method of making waterless litho available to printers. Having used ordinary silicone caulking for other unorthodox projects, I knew that it could be diluted with hydrocarbon solvents. This became the basis of my waterless process that is now used by many printmakers across the world. Because of the tenacity of the bond between silicon and aluminium, the plates produced are not as likely to become degraded as in the case of traditional lithography. Using thin aluminium plates that have been scrubbed and treated with a weak alkali, the artist produces an image from any water soluble gum or glue bearing material. Solids are applied with brush or pen. Pencil drawings are best executed with Omnichrom 108-9 water soluble pencils. The printer prepares the silicone coating by diluting caulking compounds with odorless paint thinner. This is spread over the entire surface with a soft pad and buffed to a very thin film with facial tissue covering a foam pad. Depending on room temperature and humidity, the silicone will polymerize very fast in such a thin layer. In about 20 minutes the image can be removed with ordinary water, making the plate ready for printing. Paul Constable The best ink to use in my experience is Van Son Rubberbased Plus commercial offset ink. It is of very high quality and color saturation and has the proper characteristics to be rejected by the silicone on the plate surface. While I have developed a special roller to make printing easier, a good rubber roller of the right dimensions should work. The diameter should be under 4 inches as tinting may become a problem. Again room temperature comes into play as ink will become too loose when it gets warm and cannot be lifted from the silicone. There are additives that can be used to help in such cases. So why change to waterless lithography if traditional methods have worked for over 200 years? The common chemicals used in traditional lithography may be toxic when practitioners use the more controllable processes borrowed from commercial printing. A complete procedure has been worked out for waterless lithography that reduces the use of dangerous materials to a minimum. As an added bonus, it allows the artist more freedom in producing the image and the printer less problems in completing the edition. Having practiced traditional methods since the middle 1950's until 1990, I find I have no need for them since developing my waterless process. I find it more versatile and forgiving. ________________________________________________ Copyright © 2004 Nik Semenoff Nik Semenoff Artist-in-residence University of Saskatchewan Visit Nik Semenoff's website at duke.usask.ca/~semenoff/ for more information.