Mayco Fundamentals Underglaze Class Pack Ceramic GlazesCeramics Art Supplies Mayco Fundamentals Underglazes are distinct intermixable. Apply to wet clay greenware or C 1 04 bisque. Certified AP non toxic food safe when a clear glaze is applied over them. Class Pack has 12 pints 1 every of 12 colors. Fire to C 1 06–10.