Today, I am going to share a ceramic decorating technique that was adapted from another artistic process: screen-printing textiles. Printing onto clay is not a new technique. A browse through the Pottery Making Illustrated back issues or the Ceramic Arts Daily archives, turns up lots of articles on various ways to print on clay. But the following method was a new twist that I hadn't seen before.
Though she had started out her artistic career as a potter, life’s twists and turns caused Susan Kotulak to shift gears and pursue textile arts. But the clay called her back and she now works actively in both media. It’s no surprise, then, that having this dual focus would eventually lead to the two processes influencing one another. This super cool technique is one of several that she developed for pottery using materials from her textile/surface design work. Hope you are as excited to try it as I am! - Jennifer Harnetty, editor.
Using Foam to Transfer Pattern onto Pottery
by Susan Kotulak
By screen-printing the glaze onto the foam, and then quickly pressing my bisqueware down onto it, the pot absorbed the wet glaze. By using my hands under the foam to wrap and press it up against the pot all the way around, I could pattern the entire surface of the pot, with only a single seam. By planning ahead, and selecting patterns that were not overly geometric, I was able to have even the seam disappear.
Foam is capable of stretching around curves without wrinkling or folding, reaching into shallow recesses, and carrying the volume necessary for glaze development. Unlike transfer paper, used with stains and oxides, foam can work with glaze! Transfer paper, which is often recommended for screen-printing onto pottery, can only absorb small amounts of colorants, and so is useful only for concentrated oxides or stains, rather than the volume of coating that glaze development requires. Also, transfer paper can’t conform to a round shape.
Forrest Lesch-Middelton's unique process solves the problem of how to get screen-printed images onto curvy wheel thrown pots. In his informative video, Volumetric Image Transfer on Pottery, he explains how to make a silk screen, mix the screening medium, what equipment you’ll need to create images and how to successfully screen images onto paper that’s suitable for transferring to the moist clay surface. Depending on whether the decoration is on the inside or outside surface, you’ll learn the different techniques needed to address most any form.
Tips for the Screen Printing Process
Almost any glaze can be used, simply by limiting the amount of water added, or taking part of a regular batch and letting it evaporate and thicken. I found that a pudding or mayonnaise consistency is best (see photo). If too watery, the glaze doesn’t go through the screen properly, leaking through too freely into the foam. If the glaze is too dry, the bisque ware does not wick up the glaze from the foam. A very light spray of water on the foam before the screen is printed onto it can help delay the glaze from drying before you can transfer it to the pot.
I found that transfer printing with foam was not suited to extremely fine detail transfers, such as photographs, because the pores of the foam need to be substantial enough to hold enough glaze, and that limits the delicacy of the image to some degree. Almost any foam can work, though each has its pros and cons. Larger, more open pores carry more glaze, but limit detail. Tight, dense foam carries less glaze and may dry out quickly. Thick foam helps achieve more even compression and transfer onto the surface of the pot, but takes longer to dry between uses. A small amount of glaze remains in the screen and foam afterward, and these can be washed out. Any residue inside the foam does not affect subsequent prints.
If you’d like to try this fun technique, you can buy foam at upholstery supply, fabric and craft stores. A silk-screen with an image based on your black and white art can be made up at many art-supply stores or there are many internet sites from which you can order custom silk screens. You can also buy a blank screen and use paper, tape, or other block-out mechanisms to create your image. Remember you’ll be printing the open areas of the screen, not the taped portion! To print with glaze, you’ll need a 10xx size mesh or larger in your screen so the clay particles can pass through. An inexpensive window squeegee can be used to push the glaze through the screen.
Using foam to screen print onto round pots is actually an easy process and I encourage everyone to try it. This technique could work very well with sculpture too! Happy screening onto your work!
After doing Raku firing for twenty years, Susan Kotulak now also fires her own high-temperature soda kiln, and participates in group anagama firings in her area. Completing the union of her two media, she now shows wood-fired pottery with companion textile display cloths. See more of her work at www.theokidokianagama.com/index.html.