How to Use Subtractive Layering to Make Surfaces with Great Depth Angelique Tassistro

Angelique Tassistro's intense layered surfaces came about through what we in the ceramics world call a happy accident. After spending hours creating a checkered pattern on a large platter, she dripped an unwanted blob of glaze smack dab in the middle.  

Halfway through cleaning off the platter, she saw a lovely line that was softer and less rigid, and she realized she was on to something. In today's post, an excerpt from the Pottery Making Illustrated archive, Angelique explains how she creates her signature surfaces.- Jennifer Poellot Harnetty, editor

Imagine hours spent strategically glazing one platter with the perfect-checkered pattern. Then, imagine as one of the last dots is being applied, a giant blob drips from the paintbrush splattering the perfect design. This happened to me. It was late, and I was completely exhausted! But the pressure of deadlines was ever present. At that point, it seemed the only thing left to do was to wash it all off and start fresh. And then, half way through cleaning off the platter and through the tears, I saw something quite lovely. It was less rigid, less defined, it was softer and sweeter.

Since the “incident” as I know call it, my process has evolved organically. I create bold patterns and wash them away to discover something a little more subtle and understated, yet at the same time, with surprisingly more complexity and depth. 

My surfaces are created by layering five different underglazes, one on top of another. Two colors cover the entire piece and are then complimented by three accent colors. I use a mix of Amaco Velvet underglazes and Spectrum underglazes. Sometimes I mix the two brands together to get the unique color I’m looking for. If this is your first attempt at layering color and working with underglazes, I suggest you make it easy on yourself and select five commercial colors that appeal to you. Choose your color palette the same way you would if decorating your living room. For example, choose a neutral base with a complementary partner and then pick three accent colors that go well together but don’t necessarily match. Be bold and have fun with your color choices.

Start with a clean, dry, bisqued piece—make sure all dust and dirt are washed off and have been allowed to dry overnight. If the clay is even the slightest bit wet, it won’t absorb the color properly. With a large mop brush, cover the entire piece with your base color (figure 1). It should be thick enough so you can’t see through it to the bare clay. If the underglaze is really thick, water it down and go with two thin layers. Make sure all brush marks and drips are cleaned up with either a wet brush or a sponge before this layer completely dries. If the bisque piece is dry, it will absorb the glaze quickly, and you will be ready for the next step in about 10 minutes.

Adding accent colors is one of my favorite parts because the possibilities are endless. One slight shift in color can change the feel of the entire piece. When adding accents, it’s important to let each separate color dry completely before adding the next layer of color so that the colors don’t blend. I can’t stress this enough. For this particular pattern, I fill in the circles with a sea–grass colored underglaze (figure 4) and fill any open areas or larger spaces with big circles of hunter green underglaze (figure 5) .

Next, I go back with the wooden carving tool and add more carvings (figure 6). Lastly, I add small blue-green underglaze dots to all hatch marks (figure 7) or where the carved lines connect. Of course, this is not a rule, it’s just what I do. Use it as a starting point to create your own unique pattern. Tip: The three accent colors stay more dominant if they are darker in color than the base and top layers. When you’re finished, let the piece dry overnight. Try not to let it sit for more than 24 hours—there is such a thing as too dry. If you let the underglaze become too dry, you will have to scrub it off and you will lose all of your color in the washing off phase.

Once the piece is completely dry. Gently rub the surface with a clean dry cloth to make sure there are no little bubbles left by the water or any large lumps of underglaze (figure 10). Using a black underglaze pencil, highlight the shapes and circles to further accentuate the design (figure 11). The dark pencil line will make your designs pop and give the piece depth. If you’re good with brushwork, feel free to use black underglaze and a fine tip brush. Next, cover the piece with a clear glaze (figure 12). I use two thin layers of clear transparent covered by one layer of transparent matte. Allow the glaze to dry and fire it again. Recently, I have started adding carved ledges or rims to platters and other serving pieces because I love the contrast of a black matte glazed rim opposite the wild, colorful glossy pattern of the interior (figure 13).