Linear Offset

March 28th, 2008

Principal of linear offsetRecently I have found the wisdom to again use my linear offset attachment so I could get nice flats and better detail in the fine inkjet images. I have always known that offset printing is much gentler on plates, but using delicate surfaced waterless plates makes this even more important.

Blanket in printing position A rubber blanket is glued to a Lexan tympan, which is hinged to a sheet of 1/4 inch aluminium by way of a
retractable system, making it removable to clean off
ink after finishing printing; easier than if the blanket is vertical. The aluminium support is attached to the press bed by means of pins in the side of the bed and removable pins from the top at the other end.

Adjustable pressure system

A rolled up plate is put on the bed and the blanket is brought down unto it. The blanket shows off the reflection of the ink, also the interference pigment that has offset from the print of a previous color. Offset doesn’t require much pressure; so I have added a dial gauge set up to measure just how much the scrapper bar in forced against the tympan. I use colored handles on the pressure system to make it easier to remember how much I moved the settings.

Removable hinge system

The support for the blanket consists of square aluminium that have been joined together to make a wider section needed to hold all the pieces. The sliding bolt set inside a sleeved channel has been lathed to produce a hollow to accept a cone that is secured to the tympan/blanket system. In turning the geared arrangement, the bolt puts force against two cones, giving me very a accurate hinge system for perfect registration. You can see the brass pin unto which the plate is set, and the flat brass top of the pin that holds the offset arrangement firmly to the press bed.

Pin and line registration method      You may have noticed that the plate is put on the bed at the bottom of the bed, unlike traditional press work, where it would be 180′ around. To make sure there is no shift of the plate at the end away from the pin holes, I have a scribed line on the bed, to which I add a short one on the plate when it is pushed hard up against the brass pins.

Printing by offset
In this series of pictures I am showing the rolled up plate on the bed ready for the ink to be transferred to the blanket. The next pictures shows how much richer the blanket is with ink on it. The motorized press passed the bed under the scraper bar and the last image shows the ink now on the sheet.

Press bed control

My press has two drive systems, one to move the bed under pressure and a smaller system that quickly returns the bed to rest. There are relays and electronic circuits within the control panel, which allow me to start either motor and also measure the amount of current the drive motor takes – if I need the information. My bed runs on rollers that hold the bed just off the drive roller by adjustable spring tension, which lets me put the bed into position before the scraper bar is pulled down. That allows the drive motor to pass the bed through without me having to engage or disengage any locks. The drive motor stops when a microswitch contacts a movable ramp, so I don’t have to monitor the press as I roll up a plate while the blanket is printing unto the paper. A cable pulls the bed back when I activate the return system. The white sponge is a shock absorber that dampens the bump at the end of the bed travel.

More offset printing.      This is another view of printing from the linear offset, showing how colors can be added to a print in perfect register. You can see the tabs I attach to the rag paper so that I don’t waste any of this expensive material. To have better registration, I use as wide apart pin holes as possible, but on this 15 inch wide sheet, I had to be right at the edges.

Cleaning the blanket      Cleaning the blanket is made easy by the fact it can be removed from the support so I can work on a level surface. After the rollers and slab are cleaned off, I attack the blanket with the water soluble solutions that dissolve the ink. A bit of clean water and a cloth leaves the blanket perfectly clean for the next edition.

I built this system many years ago and have used it for many editions, but lately I had got lazy about taking the time to clean the blanket, so begin using direct transfer. When I started to print on rough surfaced paper, I realized I had goofed because it was taking more time trying to not have salt and pepper in my flats. I built my press with automatic shut off where ever I placed my ramp, I could now make better use of the press while rolling up the plate for the next print.

I have also built a smaller motorized convertible press for both litho and etching. While building it, I also added a linear offset system to it as well. I had made it for my daughter who was into teaching printmaking in high school and might want to do it at her home. So far it sits in my studio, where I sometimes use it for intaglio research.

Use of Palm Press

March 13th, 2008

OLYMPUS DIGITAL CAMERA         On the edition I am printing right now, there was a small area that needed some color and I looked to find the easiest way to add it. While I could  use the common wax crayon transfer technique from Mylar I mention in the forum, I decided to try a new method that would require me formulating a special crayon.  What was needed is a soft sticky water soluble material that could be formed into crayon shapes. Amongst the material I  had was the water soluble wax used in goldsmithing to allow me to produce hollow shapes for lost wax casting. One builds up the shape close to the design, then puts on the real texture finish with casting wax to produce a thin shell to use less of the expensive metal. Water removes the supporting wax, leaving the thin model ready for investing in casting plaster. This and pure ethylene glycol, plus lampblack was my basic materials.  After melting I was able to pour the wax into simple moulds I made from aluminium foil.

I placed a sheet of Mylar over the print in register and drew a shape to fill the area.  This was transferred to a clean recycled plate using the palm press so I could regulate pressure a bit better. I didn’t press hard and only put the thicker portions of the wax unto the plate, creating a more interesting texture. Then to make sure the odorless solvent would not remove any of the image, I heated the plate with a paint stripper heat gun.  This was a precaution as my tests showed this was not necessary. Next I applied a coat of silicone and left it to  cure overnight. Next day to start printing, I washed out the image with water and rolled up the plate with a brayer.

OLYMPUS DIGITAL CAMERA          

To save the trouble of using the press, I decided to print the small textured area with a palm press by rolling over that area for a few seconds. This transferred the ink unto the rag paper to give me the effect I wanted.  Pin registration was used for each step as this is my normal method of keeping accurate color registration. You can see from the small proof on a piece of paper that the print is quite satisfactory for any edition. You can see the color added to the print on the right side of the composite picture.

OLYMPUS DIGITAL CAMERA         Again I emphasis that the palm press is not meant to print large multicolor sheets in editions of hundreds. For printing textures and special instances like this, it is fast and more than adequate for any printmaker – to save work. Small sized prints on smooth paper can fulfill ones desire for making prints if size is not a concern for the artist. I use the palm press quite frequently in similar situations where it will do the job quite nicely.

#9 Toner washes and charcoal images

February 21st, 2008


Dry copier toner images have become a common worldwide printmaking technique after I introduced it in 1985. There has 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 was encapsulated just like many of the medicines we take for timed release. It is a dirty product that most people would not like to get on themselves, and making enough toner dust is just plain carelessness.


Do not buy new toner as it can be quite expensive, but can be had from local companies that recycle and refill laser printer cartridges. They should be glad to give you all you need because it becomes a material that has to be recycled by special environmental companies that charged for this service. I can pick up good toner by the bucketful from a local company.

You should test your toner to see how solvents affect the particles. Much more is written in my university site at: http://homepage.usask.ca/~nis715/, in the toner paper. Keep in mind that the technique was developed as a replacement for grease tusche in traditional lithography.

toner proportions In a small tight lidded wide mouth bottle, fill it about 1/4 with water, then put in a few drops of wetting agent. Now add toner powder to twice the amount of water to make the container 3/4 full. Put on the lid and shake until the particles are all wet. This will be your stock supply that you can take out unto a dinner plate to mix with more water to fit the image you are planning. Depending on the supply, I have found newer toners do not require any disinfectant as mould growth has not been a problem for me.

EPSON DSC picture You will have to somehow wet the particles if you are planing to use water as the wash media, so go to the grocery store to purchase a bottle of dishwasher rinse surfactant. It is cheap and doesn’t introduce foam that can get in the way of your image. There are many good surfactants that will wet the particles to give you a nice wash, but don’t use too much as that may coat the particles so that they cannot adhere to the plate when heated or set with campstove fuel.

Foam can be used to get the popular “Skin of the Toad”, only available with French grease tusche on zinc plates. There are some detergents that will produce foam if one mixes the toner on the saucer vigorously before drawing your image. Let the wash dry on its own before heating to retain the textures.

EPSON DSC picture

I prefer to bond the toner to plates with a heat gun as all types of toner melt and stick well to the metal plate. So as not to disturb the wash if one is in a hurry, apply the heat from the bottom of the plate until all the water has been driven off, then switch to the face of the plate to bond the particles. Campstove fuel will only affect some toners, but this method is useful if the drawing is done on a plate outdoors. Pour the solvent from a bottle holding a string to prevent dropping solvent from dislodging the loose particles.

File0036

Toner washes on Mylar can be easily transferred to plate by means of a press, just like with grease images. The toner is not bonded to the plastic and the wash is allowed to perfectly dry before transferring take place. The particles can even be transferred in stages to produce a multicolour print with transfer to the first plate under light pressure to remove only the thicker areas of the image, leaving the rest for transferring to other plates in perfect registration. Use several sheets of newsprint to get an even transfer of toner; unlikely when a thicker sheet of backing is used, because of the grain in the paper. An accurate registration system has to be used to get the best prints.

toner chalk

On the university website, I explain how one can make a toner chalk that will produce charcoal like images directly on plates or on paper for transferring to plates. Good registration is needed for multicolour editions, but it will give a completely new type of image when compared to grease materials. The toner chalks can be made in various hardness depending on the surface texture of your plate or paper. This is a technique that could be explored more by printmakers after acquiring the ability to make their own chalks. This illustration is taken from a proof of a area in a toner transfer from a drawing on newsprint.

One has to use acetone to washout the image before printing starts, but many are very concerned about using this solvent. It has a TVL of 1000 parts per million and in small volumes needed to washout the toner, there should be little concern compared to children inhaling airplane glue for a high. I believe its’ greatest danger is flammability from the low flash point. Do not use hydrocarbons on the silicone surface as it is susceptible to damaged by them.

EPSON DSC picture

To reduce the amount needed to washout a plate, I have been using a retarder that prevents acetones’ complete evaporation and dissolved toner, which rebonds on the plate. After many material I have tried, I am now using automobile common brake fluid designated DOT 3 or 4. The polyalkylene glycol it contains is not toxic; about 5% added to your acetone for image washout works about right – too much reduces effectiveness of the acetone to dissolve toner. After dissolving the toner in the image, there is no attempt made to produce a clean plate surface with the solution. A cloth wet with water or soap added will give you a plate ready for printing.

There are many more features of toner that will produce interesting effects for artists, but you will have to experiment with the material you have. In my CD, there is more data on toners and how they can be used in this and other media as well. I suggest that printers ask me specific questions that come to their mind and I will try and answer them from my experience using the material for 23 years.

Copyrighted Nik Semenoff 2008

#8 Waterbased Cleanup

February 10th, 2008

Like I mentioned before, I believe ordinary oil-based ink is not toxic on its own; it is the use of hydrocarbon solvents that makes cleaning up so toxic. While I have done a fair amount of research into make ink more easily removed with waterbased solutions, I have realized these modifiers made the ink more prone to tinting in some cases.  Now I generally use none or little of the waterbased ink I had purchased. I still use modifiers, but these would commonly be removed with hydrocarbons. To give the waterbased solutions a chance to do their stuff, it is important to remove most of the ink from rollers, slabs and tools. I have developed a technique that allows me to quickly get everything ship-shape for the next printing session.

When I started printing at the universities print department, hydrocarbon solvent was ordered by 45 gallons drums to cleanup slabs and rubber rollers, which combined with the solvent based screenprinting in the department, made the place extremely toxic.  As I got more involved with the department, I realized something had to be done for students and my self to keep healthy.

  I introduced the use of common vegetable oil for remove the ink, then strong soap for remove the mess. While it worked, it was two step and students would go for the solvent container when I was not around.  Straight vegetable oil is not that effective in cutting the thick ink, so using it was a bother for students. About that time the university was getting concerned with use of solvents and a study was done on the rate of air exchange that would be needed to keep the studio completely solvent free. It would require a complete exchange every six minutes, which in our cold winter climate made it very expensive to heat the space. I introduced my wallpaper paste ink for screenprinting and started to research other media as well.

To replace salad oil cleanup, I looked at the more powerful commercial and household cleaning materials but they by themselves were not very effective at cutting into the oily ink surfaces. 

  Amongst cleaners in North America is PineSol, that smells of pine oil, which also acts as a disinfectant as well as solvent.  I found that by adding about 25-30% turpentine, it would remove thin layers of ink and the remaining film could be easily removed with water. The quantity needed mixed for the student use would separate overnight, so an effective emulsifier was needed. Again the grocery store supplied a detergent by way of an old standby – green Palmolive Original dishwasher liquid. I chose it because of a TV commercial where a lady is soaking her fingers in a bowl at a beauticians, who tells her the liquid is Palmolive. If it was safe for the ladies fingers, it can’t be very toxic. It turned out to be the best I have found so far. To get complete emulsification, a bit of the Palmolive is added to the PineSol mixture and shaken. If it doesn’t turn completely clear green, add more and shake again. This will keep clear for ages and never separate in any way. Some of the newer dishwasher liquids are not as effective as the Palmolive, but I have tried only a few – giving the rejects to my wife.

In my travel to Hong Kong and Japan, I had to find local products that would work just as well, but was lucky in both countries as grocery stores had suitable strong detergents. I believe I didn’t have to mix up solvents and emulsifiers as these cleaning agent were efficient enough on their own. This is probably true for all countries as cleaning is a necessary part of daily living. So check your grocery store first, then try industrial suppliers for their cleaning products.

citrus cleaners Over the years I have managed to find a number of industrial/agricultural detergents that work very well in much the same way as the PineSol product.  While some artists insist that turpentine is extremely toxic, I find it the best to cut into ink and not that much is added to make it a hazard in a ventilated studio. We have used artists turpentine when painting and have not worried too about the odour when released in larger amounts. The next effective hydrocarbon is common paint thinner, then the least effective is the odourless paint thinner used to dilute silicone. The secret is to add more hydrocarbon solvent to dissolve ink and an emulsifier to keep it well mixed.  

 

There have come on the market a number of vegetable based compounds for cleaning ink, in North America there is SOYsolv.  I have not had a chance to try it, but it seems to be similar to VCA in some ways. Vegetable Cleaning Agent was developed in Europe I believe and used there in industrial establishments and print shops. It has been hard to find here and quite expensive, until we found a source of Bio-diesel used for motor vehicles and is basically the same material.  It is oily and must to removed, after it dissolves the ink, with soap or detergents. I had started to make my own Bio-diesel from Canola oil, which is abundant in this area, from instructions on the Internet. Since I am not concerned with any residue left in the oil after a chemical reaction and separation, it becomes easier to make than for a motor. I was sent some VCA from Europe and have two commercial Bio-diesel products as well. While I do use one of these materials sometimes, I find the need for getting out the soap or detergent bothersome and stick to the waterbased mixtures.

To remove most of the ink on the slab, use a wide sharp scraper to leave less material on the slab, then go over the slab again with the roller to remove more of its’ ink and repeat the actions until as much ink is removed as possible. There are rolls of wet-strength paper used by various professions and try to find one wide enough to accommodate the width of your roller. Put a torn off piece on the slab over the ink area and pour out some waterbased cleaner, then roll over it until the ink is off the rubber. 

 

 

 

Using Nitrile gloves, pick up the paper and rub the roller to loosen any stubborn ink, using the sheet to go over the slab, spatulas and scraper.  A container of water and a cloth is used to attack the roller while it is moved over the slab to loosen all the ink. The roller is then passed over a sheet of newsprint on the pressbed or other flat surface to remove most of the water. A dry cloth removes the rest.

Copyrighted Nik Semenoff 2008

#7 Paper for Waterless Editions

February 3rd, 2008

Because I wonder how many read the comments, I have decided to respond to Everfrees’ concerns here. Of course, press pressure is dependant on the paper one uses and has to be sufficient to place ink down into the deeper fibres of the sheet. So that will be sort of covered later on. Because we as printmakers, do not like the ‘salt and pepper’ flats that result from insufficient ink on the plate or too hard a paper, I always wonder why we pick rough paper for printing planographic editions.

While offset proofing presses do away with this deficiency, few printmakers have them in their studios and must do with the common scraper bar presses. I have not had enough experience with printing lithographs on etching presses, so have to rely on others knowledge on this. It seems to work well enough as a number of printmakers are printing waterless litho on theirs.

If the printer is using only one colour and does not require accurate colour registration, my suggestion is to use dampened paper like etchers do. Large sheets may become a problem, but not beyond most printmakers capabilities. In the early days of my lithographic experience, I regularly printed on dampened paper in only B&W with my small stones and plates . The prints were much richer in fine detail but may appear not as rich black.

tympan hold S Smooth litho plates do not carry as much ink as the lines and coarse aquatints of etching plates. Some printers probably can get good colour registration on damp paper, but it takes a master printer with much knowledge. The scraper bar on the litho press has a tendency to squeeze the paper and stretch it a bit; wet paper is more easily affected by this action and it would be hard to hold vertical registration in a multicolour edition. Even with dry papers, this is a problem and why I modified my tympan to prevent it creeping on the press bed.

If you examine a high quality art book with illustrations of masterpieces, you will see that the four-colour separations are printed in more than 120 lines per inch and much finer in newer publications. You will also notice the paper is glossy; the fibres having been filled in with clay and sizing. The paper is then calendared to produce as smooth a surface as possible so that no small dot of ink is lost in a hollow of the sheet – and this is likely printed on sheet fed offset presses. That is one standard for excellent reproduction that some printmakers might demand, but impossible to achieve on a hand press. I have heard that there is an archival rag paper now available that is coated with clay, just like wood pulp paper, but I have no more knowledge about it. So what are we to do?

Because of my commercial printing background, I tend to require as good an impression as it possible with today’s technical advances. There are a number of good rag papers that produce excellent flats from both heavy inking and pressure of the scraper bar. How this effects dot gain in dark areas becomes another issue.

offset Because of this problem, I developed what I call linear offset for my home built transfer press, which completely does away with salt and pepper flats. Today I started a new edition using Johannot paper, which is quite rough and hard surfaced when compared even to Arches cover. On my first proof I realized I should have taken the trouble of used my linear offset option and exposed the Mylar flat as a mirror image. Now I will have to struggle with the next three plates, printing the flats I require. Because textured colours are going to be added over the flats, I have decided to go with the slight imperfections because of this, but how many times have printers accepted less than their own standards when it comes to rough paper. Some lithographers use screen media for their flats instead of struggling with of over-inking and hard time printing using a non-motorized press.

One of my more favoured papers is Arches 88, which is a waterleaf sheet that is smooth and soft to take up ink even in the shallows of the fibres. The cost of European paper is increasing in North America, because of this, others of their good papers are being used less here I would suspect. There are a number of good 100% rag paper manufactured in the United States that sell for considerably less and produce excellent editions for waterless lithographers. Of the these I liked most was Rising Mirage, unfortunately no longer available. This was a 100% calendared sheet that was smooth enough to retain nearly all of the fine detail of toner washes on the plate. Stonehenge is another 100% rag paper that I have used with success, and actually liked it as much as BFK or Arches cover. A less expensive but good 100% rag paper is Daniel Smith Lenox, which was inexpensive until the last catalogue arrived. I had printed the last few editions on 26 x 20 inch sheets, which I had to cut from the larger 26 x 40 size. I wonder how much snob appeal is involved in using European papers over those produced in North America. Just asking?

Even though I have a motorized litho press, my age is having an effect on printing the full 22 x 30 inch sheets of which I still have a large supply in my paper cabinet. I don’t believe size has anything to do with quality of an image, especially when one sees the original Dutch paintings in a museum. Etchings used to be quite small and intimate, unlike today’s demand for original art on ones walls. Taking the attitude that small is quite OK, I have decided to use up more than 400 sheets of various 22 x 30 paper by printing 15 x 22 inch sheets.

I have close to 100 sheets of Somerset, a 100% rag paper made in England, and one of the best European papers because of quality, price and smooth surface. There is about 200 sheets of BFK and 50 more of Johannot. At least 100 sheets of Stonehenge and 60 of Arches 88.

While in Japan, I was taken to a village where they still make “Washi” in the traditional way and bought some light cream coloured sheets that are just waiting for the proper image. It was December and my wife felt extremely sorry for the vatwomen working in the cold water with the Kozo pulp and their large moulds. I also have many sheets of Nepal bask paper that is brownish and rough, which was give to me by a printmaker during an earlier trip to Japan. What to do with it and the 60 or so sheets of Moulin du Gue, that is extremely rough and seems to be heavily sized, more like for watercolours than printmaking? Having 15% linen fibre might account for some of its hardness. What concerns me with this paper is the darkening in from all around the edges, even though it has been in the dark of the paper cabinet since 1985.

I have made it clear that I prefer a smooth paper for printing waterless editions, even though I have offset capabilities of handling large sheets. Paper is the usual 250 gm/m2, but I have used thinner paper with great success – as have others. As long as the paper is archival, preferably from cotton or like fibres, and smooth enough to eliminate or reduce salt and pepper areas, then it should work fine. Price might be a major factor as it usually is for poor artists.

So what how do we handle press pressure? That is hard to explain. The type of paper you are using will set the demands on pressure, as well on the quantity of ink on your slab. Unlike traditional litho where water can be used to help control rollup, waterless depends completely on the ink characteristics and amount on the slab. Build up carefully even though over-inking a plate does not ruin it, like with traditional printing. Rough heavily sized papers with require the same pressures as intaglio, but you will have to experiment with your press to get the results acceptable to you.

The simple palm press I invented for my daughter teaching waterless at high school, can produce acceptable prints under the right conditions. Professor Ozaku in Japan has managed to invent a simpler unit out of bamboo toothpicks, which will print small sized prints on smooth paper just about as good as many would like. All I can say about pressure is make sure there is enough.

There are probably other opinions out there amongst printmakers and the readers would appreciate hearing from you. Use the forum as well as the comments if you wish.

Copyrighted Nik Semenoff 2008

#6 Printing Lithographs with an Etching Press

January 30th, 2008

Traditional lithographs have probably been printed on an etching press for a long time, as Senefelder use one until the wooden roller cracked and he found that a scrapping action could work just as well. Since most printmaking seems to be done by intaglio processes, litho presses are less common; but with the ease of producing waterless prints, etchers have asked me if their presses can be used. My friend Alan Flint showed me how he printed multicolour editions for artists on his etching press – and he did this for years. I am passing on the technique with a few minor changes.

While ordinary felts can be used, he suggested a better and cheaper arrangement. Discarded offset blankets can be obtainedetching press litho from the local printer who periodically replaced slightly damaged ones. These are good enough for our use unless seriously flawed. The blanket is used with the rubber side against the back of your paper, then a sheet of thick cardboard like showcard or matte board is used as a pusher. The print is placed on the press and printed using the assembled blanket and cardboard. Use of the T-bar registration system can be OK for colour editions, but a more complicated setup makes it easier when using registration pins.

While commercial registration punches are expensive, it is possible to make do with some of the older 3-hole paper punches sold at stationary stores. These had 1/4 inch holes that fit the common 1/4 inch pins available in North America. Today, stationary stores sell punches made in Asia and these come in a variety of slightly different sized holes measured in metric. I have found good sound punches in secondhand and antique stores that fit the bill. While the extreme distance between holes is limited to 8.5 inches, this is good enough for large plates if care is taken in laying down the plate and paper.

Another concept calls for a couple of the 2-hole punches mounted securely unto a sheet of solid plywood if a wider dimension is best for your large plates. I suggest the plywood be reinforced at the point where the punches are attached, using a piece of metal bar to join them. Wood dimensions change with humidity and I have found from experience that registration is ruined unless metal is incorporated. A piece of stiff material attached to the two handles is needed to keep the punched holes always the same distance apart, because the plate can move if only one unit is depressed and released before the next one is engaged.

#Plate tab back2

I strongly recommend using registration pins if you are serious about doing colour work, especially in larger sizes. Sometimes I have felt I didn’t add quite enough ink to the plate and printing it again saved a sheet of paper, because of the very accurate registration possible.

pins Pins are available from your local printer suppliers, or can be made from short pieces of 1/4 inch brass or iron that is soldered unto a thin piece of metal. One could even make pins for the odd sized punches now being sold in North America.

intaglio pin attach

Using registration pins causes a problem as the top roller will destroy the pins during printing. To overcome this, you should make a removable bed from either 1/4 inch thick hardboard or other durable material. At one end, cut out a section so the pins can be placed in that area and below the rollers reach. A piece of an aluminium plate is punched and secured to the bottom of the temporary bed in some fashion. Pins are forced in from below so tabs glued to the paper can reach them for registration. The roller rests on the “wings” so it does not have to ride up unto the temporary bed for each print. Just make the wings long enough to give you room to put the registration tabs unto the pins.

EPSON DSC picture Tabs can easily be made from scrap Mylar or HC negatives.

Copyrighted Nik Semenoff 2008

#5 Printing the Waterless Litho Plates

January 28th, 2008

MH rolling reverse To make rolling up the plates a cleaner operation, I developed a subplate that is placed on a table near the press and ink slab, unto which one places the plate. The subplate is simply a smooth surface that has silicone applied so it rejects ink as well as the plate. Since it is best to roll completely off the plate because where you stop, there will be a small amount of ink deposited; the subplate leaves a clean area all around the plate. When it comes to cleanup time, this feature will be much appreciated.

There are a number of ways to make a decent subplate, but I believe the best is to use a piece of scrap plate glass that can be grained easily with a small piece of plate glass or small piece of litho stone and 220 grit silicone carbide. I have used one of these since the early days of my waterless research and only once in a while refresh the silicone, because this surface is used for other purposes that contaminates the silicone. After getting a decent grain all over the glass surface, just apply a coat of silicone just as for a plate.

The subplate I suggest for schools since glass can get broken from carelessness, is a sheet of hardboard. The rougher the surface, the better silicone will bond to it. First apply diluted silicone to seal the surface, then next day use silicone straight out of the cartridge and spread an even layer with a wide putty knife. Having prepared a small brayer by covering the surface with a contact plastic, roll out the high areas, which will leave a orange peel surface. This will still not be good enough so use a damp cellulose sponge to smooth the silicone as even as possible. It will cure overnight to be ready for printing.

The simplest is to use a larger plate than your printing plates and silicone it with a good film. Two can be joined with the thin plastic packing tapes now available. For more details go to my university site at: <http://homepage.usask.ca/~nis715/>.

EPSON DSC picture

For B&W editions, you can get better fine detail if you use dampened paper like in printing intaglio plates. Since most lithographs are printed in colour, then a good registration system has to be used. The best is the punched hole method that the commercial printers use, but these punches are extremely expensive and beyond most fine artists.

The next best is the T-Bar method employed by most the printers I know. There is much written on this method so I will not take the time to repeat the process, but only will add a simpler technique I figured out to replace the pencil lines on the back of the sheets. By putting the sheets into an even stack, it is easy to use an Olfa knife to cut all the way through the stack about 1/8th of an inch in from the edge, on the backside. This is repeated at the other end. Since the cut is from the back, it is closed from the front view, but can be easily seen – or by twisting the area with a finger while laying down the paper.

I have tried using the subplate directly on the pressbed, but after printing a few editions, I found the use of a glass subplate was much better than using a hardboard type on the bed. The pressure of printing distorts both hardboard and metal subplates in a short time, and the confinement of being able to use the roller from any direction, made it better to rollup in another area.

Use as small diameter roller to reduce tinting, one efficient enough to print editions. Roll completely off the plate at start and end of the pass. Sometimes there is tinting along the edge of the plate, use a clean small brayer and roll very fast over the area to lift the ink. Ink can build up on this brayer if the problem is sever, but it can be removed by rolling over a clean sheet of paper.

If you were not careful with handling the plate, there can be smudges and marks at the plate edges, which should to be removed for large editions. Just washout the ink with acetone and apply a film of silicone, then heat dry it for a while. More on this in my university site.

If for some reason the plate start to take ink within the image area, then there is hope the plate can be recovered with the use of a water based material. The first step is to remove the ink with acetone and soapy water to leave clean metal. After trying a number of materials, the best was an ink like substance that can be rolled on with a brayer. Diluted molasses that is thickened with calcium carbonate or Mag to get a reasonable film. Colour pigments are added was well and maybe a bit of retarder, depending on humidity. Start rolling up and the ‘ink’ will start to take all over the plate, but as it starts to get more tacky through evaporation, it will began to come off the siliconed surface but stay in the image.

I sometime apply a bit of heat from the heat gun, but just enough to hasten the evaporation. As it hardens more, the ‘ink’ on the silicone will get incorporated with the image and build it up more. If it gets too dry, it no longer works well and there might still be too much of in on the background. Add some water with a small finger spray and keep rolling. When the image looks full, dry the ‘ink’ to complete hardness using the heat gun, then use odorless paint thinner to lift it off the silicone. A fresh coating of silicone and curing should restore the plate more towards the original in most cases because there is likely a film of silicone still on the metal. Water removes the molasses ink and printing can continue. Molasses is used later for imaging so you will run into it again.

If the plate is to be used again for printing the image, then it should be specially prepared if the waiting time is long enough for the ink to dry completely. Wash out the ink with acetone and rub it diluted molasses, gum Arabic or some other glue that can be removed with water. Just use a cloth wet enough to leave a film in the image to prevent migration of silicone into fine detail “holes”. If there is no farther use for the image, the ink should be washed out now if the plate is to be recycled.

There can be more data on printing, but I will have to have some feedback to see what your problems are.

Copyrighted Nik Semenoff 2008

#4 Ink for waterless plates

January 24th, 2008

A good lithographic printer probably can make most traditional oil based inks available to them work in this process, but some new inks can make printing much easier.  Hand printing with waterless plates requires ink with a good amount of tack, but traditional printers normally want less tack, so ink makers keep it low. Greasy inks that were great for traditional stone and plates simply produce a large amount of background tinting so I would not recommend using these old favourites.

Luckily I was in the habit of using Van Son Rubber Base Plus ink as far back as the late 1950’s and had a good range of colours in my studio. This Dutch companies ink came on the North American market about that time, giving me a perfect ink with no drier, which I needed for the stones and plates I was using in my printmaking. When I started to do research into my waterless process in 1990, I thought fine art printmakers would reject this commercial ink, so I recommended others from their accepted list. Only after a New York art printer confessed about what he was using for traditional printing, that I started to recommend Van Son as one of the best ink for waterless plates.

#inks

Van Son makes a number of lithographic inks but the Rubber Base Plus is the one that will print cleanly many times right out of the can. It stays opened on the ink slab and doesn’t skin in the can. Colours are richer than other popular art printer inks and have passed a simple lightfastness test better than most. Luckily for printmakers, Van Son inks seem to be available worldwide.  Now Van Son and other major ink makers have started to produce special ink for commercial waterless offset printers, but the ones I have tried have too much drier that produces just as many other problems as the ink overcomes. Some have even developed waterbased waterless ink for commercial printers, but driers are still a big problem from the two produces I have tried.

There is a big push by printmakers to find good waterbased inks so they don’t need hydrocarbons for cleaning up after printing. After doing a fair amount of research into this problem by trying to modify the regular inks in my studio, I have started to wonder if all that effort was in vain. Common oil based ink by itself is not toxic as it does not have any VOC’s to speak of, it is the hydrocarbons used at cleanup.  What I had been trying was to make the ink somewhat emulsified by using common surfactants etc., but in the end I believe that there are many good industrial degreasers that can remove ink safely.  Presently I have a number of simple mixtures that will do as good job of cleaning slab and rollers if given a chance by removing most of the ink first. I will cover all this better at some later time.

Offset printers found that when they started waterless jobs, the plates would start taking on ink over the non-printing areas as the ink got warmer in the assembled ink rollers on the press.  The fountain solutions used in traditional offset had kept the plate cool as the water evaporated. Some traditional offset presses have refrigeration built into the plate cylinders to keep ink temperatures down, but even this was not good enough for the early waterless printers. Eventually special presses or conversions were developed for their industry, as well as great strides were made in ink formulation.

Ink Modifiers

 

#epoxyWhile many times Van Son ink straight out of the can print perfectly, other times some modification will makes things easier while printing. Tinting on the plate background is the common problem for waterless even though we do not have the heat build up problem by hand rolling. To overcome this the first step is to use a smaller diameter roller as the snap it produces tend to lift the ink off better from the background. Stiffening the ink with magnesium carbonate is one helpful solution, but I prefer using the hardener from regular epoxy adhesive as it doesn’t reduce tack. To increase tack, I have developed a modifier from Venice turpentine and body gum, for which a page can be found in my website at the University of Saskatchewan: <http://homepage.usask.ca/~nis715/>.

 

I also use low number litho varnishes or water reducible linseed oil made by Windsor & Newton for their waterbased oil paint. This is to get back into a usable ink if too much epoxy hardener is used, which can make the ink unprintable.  Since I have a large variety of ink collected over the many years of printing, I use them to modify any ink by the characteristics of the available inks. I have acquired a big batch of offset inks for waterless presses and use them when ever I can because I have so much – a total of 65 pound! While the driers are a big problem, I have found ways to slow drying enough to finish putting on a colour.

I have tried the waterbased inks being promoted for safer studios, but they caused many problems and some binders actually turned quite dark brown in the cans.  The Green Drop waterbased ink from a few years back actually worked very well when mixed into Van Son ink, other have been a disappointment.

#16 in roller

To make printing easier, I invented a 3-part roller that has as much snap as brayers, but has the capacity for hold enough ink to cover a greater part of the image. Choose the smallest diameter rubber roller you can find; many printers just use common brayers with great success.

Copyrighted Nik Semenoff 2008

#3 Caulking silicones

January 22nd, 2008

Silicones are organic polymers, molecules that consists of mainly of silicon and oxygen, which can be modified to produce a great number of wonderful products used by us daily. 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.

There are many silicone manufacturers worldwide so you will have to test which is best for your purpose. One thing to consider in purchasing the cartridges, is the type of closure being used. In the past the tip of the nozzle was cut off and hopefully used within a short time. This allowed air to interact with the exposed area and eventually cause the remaining material to harden. Today most companies have gone to a screw-on nozzle that is a great help for printmakers. You don’t cut off the tip of the nozzle – just the end of the cartridge and replace the nozzle after forcing some silicone into the base of it. This keeps the silicone free from hardening, especially if the cartridge is stored in your freezer. Silicones have a shelf life and this helps. Of course you will need a cartridge gun to easily dispense the silicone into a container.

To dilute the silicone to a viscosity that is easy to spread and buff, one has to use hydrocarbons and the one I suggest is odorless paint thinner. This solvent has had the toxic aromatic portion of their hydrocarbons removed, making this the least dangerous material to use. While common odorless solvents should be available in hardware and paint stores, for some reason this is not common in other countries. There is a more expensive version sold as odorless turpentine in art stores, but it seems to be the same for for diluting silicone as the paint store variety. In a pinch, common paint thinner will work but can affect some drawing materials with the remaining aromatic hydrocarbons.

You should find a small wide mouth bottle holding about 3-4 ounces and with a good airtight top. I prefer those with a half twist closure rather than screw on tops, because with use there will be cured silicone getting into the threads, making it hard to open and close the container. One type of baby food jars are perfect and can be reused if the silicone can be removed as time goes on. In humid areas, faster curing of silicone on the plate and in the closed bottle will have to be considered. One may place marbles into the partially used container to keep the air space as small as possible. They should be able to be reclaimed when mixing a new batch. I have found that unused diluted silicone will keep fluid for a long time if air is not admitted, but as one makes plates, this is impractical and so you will throw away a considerable amount of your silicone if you only print occasionally.

Squeeze about a heaping teaspoon (5ml) of silicone into your container and add about 1/4 ounce (~7 ml) the solvent and stir. Do not add too much solvent at first as you will not be able to confine the glob of silicone and break it down. 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. 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 fuller. After the glob has been broken down to be smooth and less viscous, add a small amount of odorless and keep stirring. Do this until you have added anywhere from 1 to 1.5 ounces (30 – 45 ml) solvent. Depending on the viscosity of the silicone, the final fluid should have the consistency of a light cream or salad oil. If you are using grained plates,the viscosity should be higher than for smooth backs of recycled plates.

Unless you have an unlimited supply of containers, good ones can be recycled as the silicone builds up on the inside and closure. I use a small quantity of lacquer thinner for the inside and let the container sit overnight. Next day the broken down material can be scrapped out and the closure cleaned off with coarse steel wool or a wire brush.

Coating the Plate

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. Pour a small amount of silicone unto the centre of the plate and spread it with a piece of scrap foam urethane, making sure it doesn’t remove any drawing materials. This can be noticed by a change of color if toner or dark pencils are used. Unfortunately damage to the image may have already been done – but not in all cases. 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 will be ridge marks 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 and cover one side with a double layer of 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. While silicone cures with humidity, there is still the odorless paint thinner that has first to evaporate. 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 microns, curing is fast after the solvent is gone. For a 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.

Washout of the Image

Depending on what you used for the image, you will have to use the appropriate solvent. Water is preferred, but only effective with glue binders and some pencils. For toner and lacquer based marker, acetone has to be used. Because it evaporates so fast, it can redeposit the plastic material unto the silicone and harden. This requires more acetone that I like to avoid. To prevent this, put in a retarder to keep the dissolved drawing materials soft until the plate is washed with plain or soapy water. Of all the materials I have tried, the most convenient and completely safe product is polyalkalene glycol, making up nearly 100% of DOT 3 and 4 brake fluid. Only about 5% is added to acetone to be effective as too much reduces its’ ability of washing out the image. I prefer the convenience of facial tissue for removing the image. Washout the image just before you are going to print as some silicones have enough free silicone oil present that can migrate into the finer open areas of your image and blind them.

Copyrighted Nik Semenoff 2008

#2 Drawing materials for waterless plates

January 19th, 2008

While I have time, I decided to add more information to this project. To understand waterless and its difference with traditional lithography, it doesn’t rely as much on chemistry as Senefelders original process did. Waterless is simply a delicate masking system to keep silicone from bonding to the plate. Any material that adheres well and is not affected by the odorless hydrocarbon solvent used to dilute the silicone, will form an image. Of course the safer the drawing material, the better it is for the artist. Luckily common waterbased glues and similar materials work very well. These are applied with brush, pen, sponge or anyway that will produce the type of image you like. If you look at the sample I placed into the blog posting before #1, that will give you an idea of some material that work and the sort of image they can make.

I have found that common Asian Sumi ink works well if it has enough binder to produce both brush and pen images direct on a plate. If there is not enough binder, the silicone can break through and completely change your concept. By adding sugar or any water soluble adhesive, the Sumi ink will work. The only thing really needed is the glue, as the pigment is only used for evaluating the drawing. Sugar might start to sour and become alcohol, so add some disinfectant to kill bacteria.

Other glue-like materials that work well are gum Arabic, dextrin, casein, hide glue, polyvinyl alcohol and acetate, or anything that will dry hard enough to reject the silicone application. I suggest adding a bit of Sumi ink or other coloring so you can see your work for evaluation; not much is needed.

EPSON DSC picture

I prefer dextrin because it will produce a very thin line with a thin film, which can be used easy for fine detail in a pen. I use Rapitograph pens in a number of sizes with tinted diluted dextrin adhesive. You will likely find other material that you should test first before committing a lot of work on a plate.

There are pencils that work perfectly with waterless, Staedtler 108-9 is perfect as it alone will form a rejection film for silicone. With a hardness close to middle numbers of grease crayons, it fits very well into the process. Other pencils made by Staedtler, Stabilo, Venus and Derwent, work well if heated with a paint stripping gun until they lose their gloss. The image become impervious to hydrocarbons and produces an image.

There is on the market water soluble children crayons that work well if heated in the same manner. I have three makes but you should try those available in your community. Because this blog is available internationally, I am reluctant to give names to too many products that might not be available elsewhere. Testing at your end is important.

Lacquer based markers make good drawings but have to washout with acetone, which some printers may object to using. More about this solvent later. There are a number of different manufacturers with some producing a better rejection film than others. They should be fresh capable of depositing a good film of lacquer instead of a dry-brush line. Don’t use the waterproof markers containing xylene as these will be washout completely when applying silicone.

Common ball point pens work while fresh, but have to be heated like most of the pencils. These make a fine light line that may be broken due to the surface texture of your plate. Most work, but some not good enough in my opinion.

EPSON DSC picture

Now we come to my dry copier toner technique. This requires heat or a high octane hydrocarbon to set the particles. Acetone is used to washout the image, but this will give you reticulated washes that have become common in the printing community since I introduced the technique in 1985. This includes the toner chalks that produce charcoal like images, as well as how to make them. There will be more on this technique later as it requires more detail than I am prepared to give right now.

There have been attempts to produce graduated tinted washes with the glue like materials, but that does not work. In printing the image has to be made up of small points of deposited ink, the finer the better. Grease tusche does this as the grease separates from the water as it dries, leaving tiny areas of grease that produce interesting reticulation. Glue when diluted, will still form a silicone rejecting film until the concentration of glue gets under a certain point, then the silicone gets through, forming something completely different than what you expected. There is no subtle graduation – just a rough edge where the unmanageable break point came.

Some have attempted to use poster paint tempera materials, but I have never found them good enough to do more research in that area. Since polyvinyl alcohols are probably the most common binder, they fall into the same category as using that binder alone for an solid image. Controlling reticulation seem improbable to me and I stick to toner washes with their complete control and fidelity of editioning.

Copyrighted Nik Semenoff 2008


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