Gray Air Dry Clay is an all-purpose air dry clay to use for sculpting, hand modeling, or throwing on a potter's wheel. Once pieces are finished, air dry evenly and slowly on all sides. Pieces will dry hard, but must be handled carefully to avoid breakage. Pieces can be decorated with paint, and sealed with shellac for added strength and to waterproof. This clay can also be fired to cone 04 for hardness/permanence and to glaze. Each box includes 10 lbs of clay. Sold as 2 boxes for a total of 20 lbs.