- Use a clay body with grog. Grog usually makes clay less likely to warp. (porcelain warps more easily).
- Roll your slab in multiple directions.
- Roll your slabs thick enough, the larger the piece, the thicker your slab should be to prevent warping.
- Dry slowly and evenly. I use a plastic greenhouse to dry my pieces in.
- Make/trim multiple foot rings to support the weight, create an extra one in the middle to prevent slumping.
- Make sure the thickness is even throughout the piece. You may have thinner spots where you trimmed, or near rims. Thicker rims help a lot.
- Clay has a memory if you bend or stretch it you create tiny microscopic stretch marks , it will remember.
- Dry slowly and evenly!
- Fire your plate on a flat, unwarped kiln shelf.
- Use a thin layer of alumina hydrate so the plates can slide and shrink during firing.
- Use a cookie which is made with the same clay body and at the same time as your plate. Both pieces will shrink together.
- Dry slowly and evenly!!
- ….