PlatSil 73-45 is a 1A:10B mix, mid range hardness (A~45), low viscosity, platinum silicone mold rubber. Great for making molds for all types of resin casting (polyurethane, polyester, epoxy) and foams without release agents. Used for prototyping, model making, high density polyurethane foam casting, and much more. Long mold life, high-performance, great chemical resistance and no shrinkage on cure. A very popular rubber for casting foam architectural millwork, pots, plaques and other foam décor items. Pour as supplied or thicken for brush-on molds using PlatThix liquid thickener.