Firing temperature in ceramics is measured in "cones" (pyrometric cones), which measure heat work — the combination of temperature and time — not temperature alone.
Common ranges:
- Cone 06–04: earthenware glaze firing (~1000°C). Porous body; glaze seals surface.
- Cone 6: mid-fire stoneware (~1230°C). Good for production pottery; most studio clays.
- Cone 10: high-fire stoneware and porcelain (~1300°C). Dense, durable; traditional reduction atmosphere.
The body and glaze must be compatible — they expand and contract at similar rates. Mismatch causes crazing (network of fine cracks) or shivering (glaze flaking).
Related: urushi-lacquer-technique