ComposiMold Firm 40 Ounce Reusable Molding Material, Reheat To Reuse Many casts can be made with the same mold but, when finished with the mold remelt and reuse over and over again. Made in USA Conforms to ASTM D 4236 Safe as an art material and certified food contact safe. ComposiMold Firm is compatible with many different casting materials including clays, plaster, cement, epoxy, polyurethane and many others. It's Shore Hardness is approximately 25 at 70 F Color is semi-transparent dark amber Melting temperature is 130 F.