All colors in the F-Series are LEAD FREE. CL glazes restricted from use K-6 (ASTM D-4236/LHAMA) Cone 05. AMACO® F-Series Glazes are fritted, leadless compositions. They are semi-opaque and fire with a high gloss. Colors are more intense and brilliant than those of many other glazes. Because AMACO® F-Series Glazes are leadless, they are recommended for dinnerware as well as all types of pottery made from AMACO® pottery clays. AMACO® F-Series Glazes in liquid form are ready-to-use. Recommended firing temperature is Cone 05 (1911°F, 1044°C). These glazes must be applied on a mature Cone 04 (1971°F, 1077°C) bisque by brushing, dipping, or pouring.