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Waterless lithography with water-based inksRoss Zirkle , Tamarind Master Printer, describes the latest developments. Published in and copied from Printmaking Today, spring 2000.
This new form of printmaking offers remarkable benefits to the print shop. The first is safety. Using water based inks developed by the Green Drop Ink Company (http://store.yahoo.com/safeartinks), solvents are not necessary to clean rollers, slab or plates. Consequently, hazardous wastes are not generated for costly disposal. There are no VOCs emitted removing the need for expensive ventilation systems. Green Drop Ink Company's 'AquaGraphic(TM)' Inks can be modified to print woodcut, intaglio, mono type, and screen print as well as waterless lithography.
In addition using waterless printing methods developed by Nik Semenoff, plates may be re-used a number of times. The backside of commercial plates, which can often be obtained at little or no cost, can also be used over and over again, as many as thirty times. This is a substantial saving to either an educational shop or a professional print shop. These waterless lithography plates may be editioned by hand or with a letterpress, etching press, and or lithography press. There is a printmaking revolution about to begin. It will be waterless lithography using water based inks. As a research assistant at the Tamarind Institute, I could see the benefits of water based inks for the printer in addition to safety, environmental, and cost issues. Any form of rejection either wet or dry does not effect water based inks. Water based inks make cleaner, crisper, transparent colors. Water based inks have no oils in them so there is no traveling of oils to the back of the print. Another benefit of having no oils is they are more stable. You will not have to worry about bronzing colors or colors changing as dramatically with drying. The colors appear to be as permanent as oil based inks. Green Drop inks drying time is very flexible with a much greater range than oil based inks. The future for printmaking (particularly lithography) is here now with these water based inks.
THE FUNDAMENTALS OF WATERLESS LITHOGRAPHY
In traditional lithography, water is used to repel oil based inks from the non image areas of the printing elements. In waterless lithography the non image areas are covered with silicone that also will repel oil based ink. While I was at Tamarind I became intrigued by the possibility of using water based inks with the waterless printing process. This is a simple idea but in practice proved to be very difficult to achieve. The problem was that water based inks usually dry too fast to effectively ink up the printing element. If the water based ink was modified to retard drying, it lost the tack that is necessary to print waterless lithography. I have been working with the Green Drop Ink Company to develop the proper modifiers to overcome these obstacles to water based waterless lithography. Today we have a very workable system of ink and modifiers that: should if properly used provide a safe, economic and reliable alternative to oil and solvent based traditional lithography.
If you already use waterless lithography in your shop, you will have to make some changes to the way you print waterless to print these water based inks. The first thing you will need to consider is your plate selection. The smoother the plate the less scumming you will have on your non image areas. I prefer aluminum plates without a ball grain. I in fact, prefer to use the back of used commercial plates. We are all indebted to Nik Semenoff for this latest development. Nik discovered that these smooth plates could be given some tooth by scrubbing them with ordinary cleanser and water. I use a sponge for this process and then rinse the plate with clean water. The next step is to coat the plate with a diluted solution of sodium silicate and water using a clean sponge. Once the plate is evenly coated with sodium silicate, rinse it off with water. The final step is to blot and let the plate air dry. They are now ready for use.
When your image is ready for plate processing there are some important differences in processing a plate to be printed with water based inks. You will need a slightly thicker coating of silicone for water based inks than what is necessary for oil based inks. Mixtures of 70 percent odorless paint thinner to 30 percent silicone works the best for me. Do not go over board with thickening your silicone or you will loose some of the subtlety of your images causing them to have too much contrast. I recommend GE silicone or Dap 100% clear rubber silicone in the blue tubes. Nik Semenoff recommends Dow Corning silicone 999A. Use whatever brand currently works for you. I have not tested them all.
Besides the thicker silicone, coating extra care must be used in processing a plate for water based printing. Water based inks actually do print more detail than is possible with oil based inks. This fact can work against you if you are careless about how you apply your silicone. I use a sponge for spreading the silicone and a separate clean sponge wrapped in Kleenex for buffing the silicone cleanly and evenly. Every fingerprint or variation in silicone thickness will print with water based inks, which is another reason you should not apply your silicone to thickly. If you are using punch registration, hold the plate near the punch holes. If your print is a bleed print, hold your plate outside your image area. If your image has spots where fingerprints would not show such as heavy toner washes hold your plate down in these areas while applying silicone. I have developed a technique of buffing silicone down that looks very similar to wiping an intaglio plate. I do not actually grip the plate but let the palm of my hand support the plate while I pull the sponge towards me. Once you have mastered this technique, you should never have another finger print in your image.
CURING THE SILICONE
I really think the best way to cure silicone is to let it cure naturally at room temperature. I usually wait twenty minutes between coats if I am going to double coat them, which I recommend on grained plates. For plates that have no grains such as positive photo plates or the backside of any aluminum plates I usually only need one coat. These single coated plates are usually ready to print in an hour if rushed. I usually leave my plates cure over night. If you are really rushed, an oven set at 250 degrees will do the job in ten minutes. A hot plate will work but you must avoid hot spots in these, which can effect some photo emulsions and drawing media such as Sharpie, which if over heated will not wash out. If you can raise your plates off the hot plate using old oven racks, this is helpful. A non-flammable box placed over your hot plate makes a fairly good oven. A heat stripping gun will work too. The gun must only be used from the bottom of the plate. I must stress I prefer a naturally cured plate because a heated plate besides the possibility of damaging the drawing media can also warp the plate causing you registration and rolling problems during printing.
ROLLING OUT YOUR INK
I like to roll out my ink before washing out my image. There are several reasons for this. I like my water based inks to tighten up a little on the slab before inking the plate with them. In fact, I often mix my colors the night before printing for the same reason. I store my inks in loosely fitting containers such as petri dishes. The other reason is I do not like to have a freshly washed out plate left in an open state. This can cause some damage to the image especially in a plate in which the silicone has not been totally cured. When rolling out your ink I recommend Nik Semenoff's three-part Roller. These handcrafted rollers are the most efficient rollers on the market for waterless lithography. The smaller inking rollers provide much more snap than larger diameter traditional lithography rollers. The feeder roller on the three-part roller system will give you the same reach as a traditional roller. If your shop does not have a three-part roller, brayers that are fairly hard will work too. Some of my students actually prefer brayers for smaller plates. Whichever roller you use, I recommend keeping your slab lean. A lean ink film will generate better tack than a thicker slab. Once your slab is rolled out evenly, you are ready to proceed to testing your ink on the sub plate.
ROLLING UP ON A SUB PLATE
I have never found a better way to roll up your plate than on a sub plate. A sub plate is a surface that has been siliconed to reject ink. I recommend a grained thick slab of tempered plate glass for two reasons. First, as the Harvey Littleton shop can verify glass and silicone are a very good match. At the Littleton studios, they actually print waterless lithography from glass instead of aluminum. The glass is a excellent rolling surface that repels ink exceptionally well when siliconed. The second reason I prefer glass is its weight. Glass will not move around as easily as say a Masonite sub plate, which is my second chose. Masonite sub plates are also less effective at repelling ink, because the silicone must be applied to the textured side to hold, which is too textured for efficient use with water based inks. The sub plate allows you to roll past your printing plate depositing a line of ink that is always left at the end of your roll, in this case off your plate. This invention of Nik Semenoff is a God sent for the waterless printer. It works best with small diameter rollers. Because of the tack generated by waterless inks avoid those large diameter traditional rollers as they actually can lift your plate off the sub plate wrapping it around circumference of your the roller. Roll up is the moment of truth to reveal first if your ink is properly modified, second has your plate been properly processed, and thirdly have you selected the proper roller for the element you are about to print. I prefer not to have so many variables on roll up. I do my best to determine that the ink is properly modified before I roll up. This is easy to accomplish by rolling a fully inked roller across your sub plate. If your roller leaves a stripe of ink reflecting no rejection by the silicone, you know you are headed for trouble when you ink up your printing element. Modify your ink by adding some of the Green Drop body additive. I usually roll my water based ink longer on the slab before going to the sub plate than I would if using an oil based ink. These inks will develop tack caused by the mechanical motion of rolling them, this is especially true if you are using a three-part roller. Its important to remember that a lean slab that has sat for a few minutes is going to yield the best results. You can determine that your inks are correct when your Inked roller leaves no ink on the sub plate except for the places you begin and end your roll. At this point, you should proceed to your wash out.
WASHING OUT YOUR IMAGE
I recommend using Kleenex to wash out your plate, so as, not to scratch your image. Water soluble materials such as Staedtier Omnicrom pencils #108-9, gum flats, Sumi ink, and tempera washes can all be washed out with water. All the excess water must be removed from your plate before you roll your plate with water based Inks. Photocopy toner dust, chalks and washes are best washed out with acetone using gloves and adequate ventilation. Other more costly solvents will often work such as winter green oil, as well as some citrus solvents. I recommend acetone because it leaves no oily residue that may interfere with the inking of your plate. Remember the plate should not be stored in an open state after wash out for any length of time, especially after the initial wash out when you may have rushed the curing time of the silicone.
TROUBLE SHOOTING PRINTING PROBLEMS
You are now ready to ink your plate. Start your roller on the sub plate off your actual printing element. Its best to roll fairly quickly across your plate not stopping until your roller is completely off your plate resting again on the sub plate. This rolling pattern is repeated until your plate is fully inked. If your plate takes ink properly you can relax and enjoy the run. It is now time, to move your fully inked plate to your press bed for your first impression. If your plate is scumming badly, roll your plate vigorously with clean brayers to clean it up. Sometimes with just this step and some proofing, your plate will straighten up and the cause may have been your plate was not properly washed out. If your plate still is scumming badly then its time to assume that you may have applied your silicone to thinly. In this case ail you need to do is clean up your plate as much as you possible rolling it with small brayers. Then add another coat of silicone leaving 'AquaGraphic' Inks in your plate to protect your image. Do not worry if you cannot totally clean up all the non image areas. As these areas will clean up in the process of applying fresh silicone. Adding another coat of silicone will improve the ink rejecting property of your plate. I recommend that you do not heat: cure your silicone as these water based inks will not wash out if you over heat them. If you have the opposite problem from scumming and your plate does not take ink, roll slower and add a little downward pressure. If it still does not take ink loosen up your ink with Green Drop tack reducer. If your plate still is not taking ink, you might conclude that the silicone did not cure long enough before wash out. This would allow the silicone to travel from the non image areas to the image areas causing the entire plate surface to reject ink. If you lose a small portions of your image sometimes these can be replaced in another color run or they can often be added back into the original plate by scratching away the silicone were It doesn't belong.
WHAT ABOUT OTHER PLATE PROCESSING ERRORS?
If you find that you have fingerprints in your silicone coating, or if, you missed applying silicone a portion of your plate. Then you must clean out the ink in those portions of your plate with a degreaser diluted with water before adding silicone to those areas. Your plate should then be left overnight for curing. Deletions you wish to make in your image area are handled the same way. This step should not be rushed. The affinity these inks have for metal makes them print well, at the same time, this same property can make deletions trouble some. Another common problem is applying the silicone unevenly, this will cause the valleys in your silicone to take ink and print. I have found that increasing the tack of your inks with body additive will work. I prefer to try rolling the plate in the direction of the ridges first. This will often take care of the problem with out causing new ones such as developing to much tack in your inks. What happens when the Ink has too much tack is that the print will start to look under inked and your rollers will begin to push the inking slab and the sub plate around as your roll on them. If this happens Its time to add Green Drop tack reducer. It is normal for this ink to gain some tack in a run. In this situation, the solution is to scrape back the slab and put fresh ink out. I usually scrape back my slab at least once in an edition.
STORAGE OF PLATES
At the end of proofing or editioning, I usually just leave my Ink in the plate. Usually if the plate does not set out for more than a month, the plate will wash out with a degreaser. If the plate has set out for longer then it may be necessary to use a small amount of acetone to assist washing out your ink.
TIME AND MONEY SAVINGS
With these 'AquaGraphic' Inks, you can run your next color immediately or you can wait several years as there is no wet or dry rejection with these inks. Clean up is so fast with water based inks that you can often clean up and print that next run in the time It would have taken you to clean up a solvent based ink run. These facts make proofing a dream in the professional shop where your artist is anxious to see the results of his efforts quickly. Over all, the waterless lithography process is much faster than traditional lithography which allows more time for experimentation, and more color runs, which should produce better prints which are actually cheaper to print.
THE EDUCATIONAL WORKSHOP
Every teachers knows that the most hazardous time in the workshop is clean up. It is possible to have at least five slabs and twelve to fifteen rollers to clean up at the end of each class period. If you are using solvent based inks, means there is a substantial amount of solvents in the air. If you use Green Drop water based inks, every thing can be washed up with soap and water. For an educational workshop, this water clean up is an extraordinary benefit. I introduced these inks Into my beginning printmaking class last fall at Asbury College I have never been happier with an ink selection. It takes my students just five to ten minutes to clean up the entire shop without having to use any solvents. I taught my students how to use water based inks first and then taught them to use oil based inks. They overwhelmingly preferred the 'AuaGraphic' water-based inks. I think if you show your students how to use them properly they will also chose to use water based inks as well. You will not have to worry about stocking solvents, running a rag service, or keeping your MSDS labeling current. These inks are safe to use even without gloves. You have an a safe alternative now from the way things are. Your students will thank you for making the change and you can sleep at night knowing you have provided them the safest printmaking practices possible today.
ABOUT THE AUTHOR
Ross Zirkle is a Tamarind Master Printer who is an adjunct professor of Printmaking at Asbury College, and the University of Kentucky. He has presented the use of Green Drop water base inks with waterless lithography at the Mid America College Art Association Conference in Lexington last October. At that time he editioned the world's first collaborative lithographic print using water based inks for Ecuadorian artist Nelson Santos. Ross Zirkle will next be presenting the use of these inks at the Southern Graphic Council Conference to be held at Arizona State University, March 19. He welcomes your comments on the article. He may be contacted by e-mail at safeartinks@bigfoot.com.
Article and pictures, Copyright Ross Zirkle 1999
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