Slip decoration has been a favorite surface decoration method for many years and, over time, gravity, began to play a large role in the way I would apply my slip. My slip technique mimics the valley and mountain landscape I find at home in southwestern Virginia. In every work, I see peaks and ridges of far off mountains cut by wide rivers. I see my glaze design as another element to my landscape story. The glaze runs and pools over the surface of my work mimicking the way water rushes over the rocks in the river.
I use a variety of slip consistencies for multiple effects; in combination with a wide range of tools, I’m able to achieve exciting slip designs. Each piece is unique because working with slip always has an element of unpredictability; no two slip marks are the same. The more dramatic and unexpected a mark, the more I like the work. I find small variations and exciting textures highly desirable. Use of tools, slip consistency, and gravity all work together with lines and textures to produce a creative, fluid form.
Any slip can be used for this technique, but I find porcelain or white stoneware work best. This preference is attributed to the finer particles in these clays leaving a smooth, clean texture. I make slip from my trimmings to ensure I’m using the same clay body to reduce shrinkage issues. The trimmings are slaked down and mixed using a jiffy mixer. Once mixed, I check the slip for any lumps. If the slip is lumpy, I pour it through a 30-mesh sieve; this process creates a fine finish to the slip. I take care not to add too much water and keep it at a pudding-like consistency. I like my slip to be fluid enough to flow off my hand (A). Having different slip consistencies will yield different results. Thin slip leaves faint smooth lines, whereas thick slip leaves thicker marks and texture.
Considering slip is not a new concept, it’s important for me to experiment with multiple application techniques. It’s not uncommon for me to shift or tilt my forms to achieve more exciting and dramatic slip designs. My favorite mode of application is applying slip to an inverted pot. Gravity pulls the slip down, creating ridge-like marks. I use a number of different methods and tools to create a variety of marks on each pot (B). I love the combination of textures and lines the tools form with one another.
First Slip Application Method
Slip can be applied to wet or to leather-hard clay. I prefer to apply slip at the leather-hard stage, because it allows me to trim the pot without disturbing the slip. I add slip directly after trimming; if the pot is too dry, the slip will crack. If cracks form around thick to thin areas, take a pencil or rubber clay shaper and compress the cracks. This method helps prevent the cracks from opening up further when fired.
I keep slip in a small, two-gallon bucket, which allows it to be easily stirred by hand. If you find your slip has thickened since you last used it, add a bit of water to get the right consistency and stir it again. Up-end the form and center it on the wheel before applying slip. My first method of application is to scoop the slip out with my hand and apply it to the spinning pot (1). Start at the top (which is actually the bottom) and cover the surface until about halfway down. Once slip is applied to the desired thickness (no more than 3⁄8 inch), you can begin decorating. Note: From this point on, the wheel is stopped and only moved by hand.
Using a chip brush and starting on the pot just below the slip, swipe up while turning the wheel counter clockwise. Each swipe will cause the slip to drip (2). Continue this all the way around the pot (3). Clean off any slip that remains on the foot (4). Leave the pot to dry for about an hour, then flip it right-side up (5). Press down or wipe away any sharp drips that are still malleable. Once the slip is dry enough, cover the pot loosely with plastic or a bucket.
Second Slip Application Method
The second slip application method is applied to a pot while it’s right-side up. Adding the slip as before and using a similar brush, hold the brush horizontally as the wheel spins. Move the brush up and down, starting at the top and slowly descending to the bottom (6). This motion pushes the slip down, creating thin and thick horizontal lines (7).
Third Slip Application Method
The last method is, again, done with the work right-side up. This application uses a flexible rubber rib and thicker slip consistency. Swipe the rib up from the bottom to the top, repeating the strokes around the entire pot (8). The thicker slip creates a denser line which doesn’t drip in comparison with the previous methods (9).
Glazing is the final element that makes or breaks a pot with slip decoration. I strive for a finish that is a combination of matte and glossy glazes in a variety of colors that break against the slip texture in beautiful and unpredictable ways.
With the pot set on a banding wheel, it’s initially sprayed with a base crystalline glaze, which creates a matte micro crystalline surface. I add food coloring to light-colored glazes that are difficult to see. I hold the spray gun 8–10 inches away from the pot, moving it in a circular motion (10). Saturated color is added using watercolor glazes, which have the ability to create a colorful, glossy finish. These glazes can be made in a variety of colors and tend to run easily, creating the exciting movement I strive for in each work. I use colors such as light blue and yellow to highlight small areas, while blue, green, and lavender are used on larger open areas. These small and large areas melt together creating subtle color changes. I strategically spray to emphasize drips and slip texture using these watercolor glazes. Apply the glaze just above the slip mark using low air pressure to create a controlled application. Once fired, this will cause the glaze to break over the texture for unexpected results.
I fire my pots to cone 6 in an electric kiln using a slow cooling program, which helps the crystals develop.
The exciting and dramatic interaction between slip and glaze is the ultimate goal for my work. With the combination of slip and glaze, you will find endless possibilities for striking, unique designs.
Chris Lively is a studio potter currently living in Virginia. He has exhibited in such shows as Beyond the Brickyard at the Archie Bray Foundation for the Ceramic Arts and at the Strictly Functional Pottery National. To see more of his work, visit www.chrislivelyceramics.com.
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