Understanding Clay Shrinkage
Clay shrinks in three stages: wet to bone-dry (water evaporation), bone-dry to bisque (chemical water loss), and bisque to glaze firing (vitrification). Total shrinkage typically ranges from 10% to 15% depending on the clay body and firing temperature.
Typical Shrinkage Rates
- Earthenware: 4-7% wet to dry, 0-1% bisque, 1-3% glaze = 5-11% total
- Stoneware (Cone 6): 5-7% wet to dry, 1% bisque, 4-6% glaze = 10-14% total
- Porcelain: 6-8% wet to dry, 1-2% bisque, 5-7% glaze = 12-17% total