A polymer modified, fiber reinforced gypsum cement created from a hydrostone base. Has much better flexural and impact strength than unreinforced material. This is a very fine grained gypsum cement, off white in color and very dense. Retains high compressive strength of base material and is normally used for making high detail castings. Not recommended for "building", this material does not have a period of plasticity and works best when casting into rubber molds, and must be tooled immediately upon removal from the mold as it becomes very hard on curing.