Here's how to do it:
1. After your piece has reached leatherhard, and you have finished trimming it, paint a coat of slip onto the pot while it is centered and turning on the wheel. Do not paint the rim. Then invert the pot and repeat the procedure on the back side. Do not paint the bottom edge of the footring.
2. Allow the slip to dry to the touch, and repeat step one, by adding a second coat of the same (or a different) slip to the inside and outside of the pot.
3. Allow the slip to dry to the touch again. It will take longer this time. Be careful in handling the piece now, as it has absorbed water from the slip and will be softer and more easily distorted!
4. After the second coat of slip has dried to the touch, you may begin to carve designs. You may band circles onto the pot while it is centered and spinning on the wheel, or just free hand carve, or both. Designs may be lightly carved at first with a needle tool so that changes can be made. If your design is one that repeats symmetrically, it is best to outline a grid on the pot before carving. This will be demonstrated for you.
5. After carving is complete, put the piece on the greenware carts for drying and bisque firing.
6. After bisque firing, glaze the piece simply with a transparent or semi-transparent glaze so the carved design will show through.
T''zu-Chou vase, Chinese, Sung Dynasty (11th-12th century AD) sgraffito carved through a white slip to a stoneware body
Harrison McIntosh, USA, Plate, 1978
Stoneware Plate with Sgraffito design
