These are UV printed on PETG plastic and slump molded into a small tray. PETG is indeed food safe but the bowls can only be lightly cleaned. They are not durable enough for daily kitchen use. They are an art object and not a functional kitchen bowl. Gentle use is recommended. Each tray is unique because they are hand molded. The bowl starts out as an 11″ disc that is molded. So the bowls are about 9″ with 1″ sides.