Ideal for drawing on or identifying artwork. Apply to bisque ware and create unique, detailed designs. Black pencil has a maximum firing temperature of Cone 10, and offers stability for low firings, even without a clear glaze. Unsharpened. AP Seal, non-toxic. If left unglazed, Underglaze Pencil should not be used on surfaces which come in contact with food or drink. Food safe only when applied and fired under AMACO LG10 Clear Transparent Gloss Glaze.