Our antique moulds are hand crafted from the original element so you get a perfect impression. We use 100% silicone mould material that does not stick to metal clay, or any other type of clay, so no release is needed. They can be placed on a heat source to dry clay, or be placed in an oven or toaster oven. Our moulds are safe to 500ºF. Use the moulds as stampers or impress small bits to create a collage. The photo shows a finished piece made from fine silver clay. It has been oxidised to give an antique appearance with Cool Tools Patina Gel.