Mold release is required on some molds to release the cured casting. It is strongly recommended for all polypropylene and rubber molds so your castings pop out of the molds every time. Keep your molds in good condition by using CASTINCRAFT MOLD RELEASE AND CONDITIONER to clean and extend the life of the molds. A little goes a long way! Want to use your molds over and over again? Use CastinCraft MOLD RELEASE AND CONDITIONER for easy mold release.