Published Nov 8, 2017
Brad Menninga was interested in screen printing on wet clay, but didn’t want to mess with screen printing medium or long drying times to get his “inks” (in this case a glaze) to the consistency at which they wouldn’t run. So he thought, why not start with dry materials?
So he came up with a process in which he screens a dry mix of a clear glaze and Mason stains onto damp newsprint, and then transfers the print onto a slab of clay. In today’s post, an excerpt from Image & Design Transfer Techniques, he shares this process. –Jennifer Poellot Harnetty, editor
P.S. The full article, including how to burn a silk screen, is included in Image & Design Transfer Techniques.
I took, perhaps, the most indirect route to making prints on clay, and that, with a nod to Robert Frost, has made all the difference. It happened like this: for many years I’ve been firing with Richard Rowland in his Astoria Dragon Kiln, an anagama-style wood kiln that typically fires for over 100 hours with temperatures in the cone 11–13 range, and a lot of ash. Several years ago, the kiln developed a problem. The back of the kiln was struggling to get to temperature—the pots in the back third of the kiln had decent ash and flashing on the front-facing sides, but the backsides were anemic and lifeless. I decided that silkscreened images would be the solution to pursue to bring the backsides of these pieces to life.
I had three technical goals for the process I wanted to develop. First, I wanted to manipulate the printed clay, so it had to be printed while the clay was still workable. Next, I wanted the prints to survive high-temperature firings, including wood firing. Finally, I didn’t want to mess with solvents, oils, decals or other products that might produce irritating fumes or messes.
Jumping right in, I naïvely assumed that printing on clay would be just as easy as any other kind of screen printing. The silkscreen process gives a nice sharp image because while the wet ink is squeezed through the screen, the dry paper or fabric binds the pigment into place. The problem with trying to screen wet, ink-like glazes onto wet clay is that the clay doesn’t absorb any of the glazes—it will just smear the glaze all over the clay surface.
The solution was to reverse the wet-onto-dry screen printing process, and to print with a dry blend of pigments and glaze ingredients onto wet clay, giving a nice sharp print. This solution evolved into adding the intermediate step of printing with dry pigment onto damp newsprint, then rubbing the newsprint onto clay, leaving a transfer print, like a temporary tattoo. Since the paper can wrap around simple curves, it allows me to print on rounded forms, like wheel-thrown cylinders.
After the transparency has been burned into the screen, washed out and dried, it is ready for printing. For printing, I mix 50% Mason stains with 50% clear glaze (dry). The clear glaze helps fuse the print on during the bisque firing.
My work surface is a sheet of glass placed over a lig htbox. Dampen a piece of newsprint on the glass with a wet sponge. Smooth out any wrinkles or air bubbles, then blot away excess water with a clean cloth (figure 2). The newsprint should be wet but not so wet that water can be squeezed out of it.
Place the screen over the damp newsprint and sprinkle black pigment onto the screen. Use a stenciling brush to push the powdered pigment through the screen onto the newsprint (figure 1). Depending on the openness of the screen mesh, you may need to go over the screen several times to get enough pigment through onto the paper. Remove the screen to reveal the black channel printed (figure 2).
The trick is to use the right amount of pressure on the brush and to keep the screen close to the paper without touching it. If too much pressure is used, the screen will touch the wet paper and the pores will clog. If the screen is too far from the paper the pigment will spread out as it falls, creating a blurry image. Make sure your screen is tight and unwarped and use shims or weights to hold it about two millimeters above the surface of the paper. If the screen gets blocked or the print looks too light, use a dry brush to clean both sides. Use the lightbox to line up the screen with the already printed image to screen more pigment where needed.
To print with more than one color, there are two possibilities. Different colors can be brushed through different areas of the same screen, like brushing colors onto a woodblock for printing. Or a more precise way to use multiple colors, necessary for color halftones, would be to use a different screen for each color. Be sure to create registration marks on each screen so you can easily line them up. Use the lightbox beneath the glass to help line up the second screen (figure 3). Start printing with dark colors first and finish with light. While four-color printing is possible, good results can often be achieved with only two colors.
Work quickly and carefully so that all the colors are printed on the paper before it dries out. Check the quality of the print on the paper before transferring it to the clay (figure 4). The order of the layers of color will be reversed when transferred to clay. If it’s unsatisfactory, set the paper aside to dry and try again. When it has dried, the pigment will easily brush off and the paper can be reused.
Transferring the Print
When the print on paper is good enough, carefully spread the newsprint onto the clay, print side down, avoiding wrinkles or bubbles. The clay should be wet to leather hard. Use the back of a spoon or a burnishing tool to rub the print onto the clay (figure 5). Slowly peel the paper away, checking to make sure all areas of the print have been transferred to the clay (figure 6). Avoid touching the printed surface until the clay has been bisqued. Place the printed slab face down onto an internal plate mold and trim off the excess clay (figure 7). Compress the slab into the mold using a wheel, then throw a foot ring. After the plate has set up, it can be taken from the mold and cleaned up (figure 8).