Polar Porcelain Cone 6 Clay. A lower firing range porcelain great for throwing and hand building. Also very popular for making jewelry - compatible with our P-Series colored porcelain clay. Fires Between Cone 5-8, 2167-2280° F. Shrinkage rate is Cone 5 - 12.5%, Cone 8 - 15.0%. Best use is Throwing, Hand Building, Jewelry Making.