Published Jan 5, 2022
I have been really into handbuilding and red earthenware lately—in particular, using hump and slump molds to create forms. Today’s post is sort of a perfect marriage of those interests. In it, Shoko Teruyama explains how she creates her forms using coils and slabs over bisque molds.
Plus she shares how she coats her pieces with slips and carves intricate drawings into them revealing the red clay underneath. – Jennifer Poellot Harnetty, editor
I create handbuilt forms using bisque molds. The premise of using bisque molds is not to quickly produce a lot of work, but quite the opposite. It’s about slowing down the process, examining the form, and touching everywhere to create well-thought-out pots. I like my work to have a thicker wall on the bottom and taper to a thinner rim on top. I touch the entire form to make sure there’s a smooth and consistent transition from thick to thin. In addition to the changes in wall thickness, I work with contrasts in surfaces. The textured area on the outside is a place for your eye to rest and contrasts with the highly decorated surface that will be on the inside.
My bird boat form was developed in response to a historical wooden boat that had a bird figurehead on the bow. At the time, I was using bird imagery in my surface decoration and wanted to incorporate the imagery into the actual form. I am interested in how the three-dimensional bird head points in a given direction, and how the head and tail combined elongate the boat, and activate the form.
I use a variety of bisque molds as a starting point. They are made by mounding stoneware into a desired shape, carving them out, and firing them to cone 08. It is important to use a porous clay body and only fire it to bisque temperatures so it will absorb moisture from slabs wrapped around the mold.
It is very important to begin with an even, well compressed, and thick slab. Make your slabs 1/2-inch thick by pounding a ball of clay with a wooden mallet or paddle (figure 1). The repetition of pounding and flipping compresses the clay particles and creates a strong slab that will not crack. For larger slabs, pound two or three balls of clay together. Make your slab two inches wider than needed to cover the bisque mold (figure 2). Use a rolling pin when you are done pounding to smooth the slab out.
Making the Form
Place the slab over the mold. Use both hands to press the slab against the mold, removing all trapped air. Use your finger to compress around the edge of the mold and make a slight indent. Cut outside the finger mark and remove the excess. To strengthen the edge of the slab, first merge the clay flange in toward the mold and then up into the slab using a serrated rib (figure 3).
The finished piece has a foot that elevates the form, so score and slip a row of coils on top of the dome (figure 4). Use a wooden disk to smash the coils down evenly and level to create a flat base. Use a serrated rib to merge the base into the slab, making a smooth transition into the body (figure 5). Using coils to build the solid foot works much better than using a slab because the coils do not trap pockets of air when they are attached. Working the serrated rib in a crosshatch pattern erases the clay’s memory of being coils and no cracks appear during drying or firing.
Leave the form and the mold together until the form is a soft leather hard, or firm enough to hold its shape. Remove the boat from the mold and cover it with plastic overnight to even out the moisture.
Refining the Form
When the boat is soft leather-hard, use a Surform to shave away excess clay, remove bumps, and create a strong curve (figure 6). Define the foot by trimming it with a stiff serrated rib. Continue to use the rib in a crosshatch pattern to refine the form and create a texture on the surface (figure 7).
When the form is turned right side up, attach two coils to the rim to add extra volume to the form (figure 8). Curve the coils in slightly to add height and enclose the volume. Leave it for a few hours to reach leather hard and then continue using the Surform and serrated rib to refine the inside of the form.
Making and Attaching the Bird
Using a ¼-inch thick slab, cut out the shape of a bird head and tail using a tracing paper stencil. Cut out two of each shape. The two bird heads need to be a mirror image (figure 9). Bevel the edges at a 45° angle. Push out the middle of each piece to give them volume, score the edges and attach two halves together (figure 10). One edge on each piece is left open. Use a small coil to reinforce the inside of the joint. Push a little more from the inside to give a puffed feeling. I use a wooden spatula to tap the bird head gently and make it more three-dimensional. Leave both parts uncovered until they reach a soft leather hard.
The head and tail are dry fitted (without scoring and slipping) to the body by cupping the opening around the rim (figure 11). Once the head, body, and tail are lined up, trace around the joints. Score within the traced line apply slip and reattach. I leave the attachment edges exposed instead of working them in to keep the definition of each part visible. The head is supported until it becomes leather hard (figure 12). Poke a hole into both the head and the tail to allow air to escape during drying and firing.
Designing the Surface
As soon as the piece reaches leather hard, apply green slip over the bird head and tail and brush white slip onto the interior surface with a fluid motion (figure 13). This creates depth in the slip that is revealed after the glaze firing. Allow the piece to dry slowly and completely.
At the bone dry stage, sketch out a decoration onto the white slip with a pencil. I often use flying birds in the decoration as focal points to lead the viewer’s eye around the form. Between the birds are different patterns of motion that allude to wind or water (figure 14). The two motifs create rhythm and activate the interior space.
Use an X-Acto knife to scratch through the slip revealing the red clay. The process creates a lot of fine dust and it is important to not blow the dust away and into the air where it can be inhaled.
I use translucent colored glazes over the sgraffito decoration so the marks stay visible and thicker opaque glazes over the textured areas for contrast.