Poly 74-30 Liquid Rubber is a two-part, liquid polyurethane system that cures (RTV) to an amber (color varies), Shore A30 rubber. This is a pourable rubber, but it can be easily thickened with PolyFiber II Thickener for brush-on application. For a transparent, amber version of this rubber, consider Poly 74-30 Clear Liquid Rubber. This product is useful for molds where clarity is needed to see casting material fill the cavity. This liquid polyurethane rubber can also be used for casting clear amber or color-cast flexible art objects and décor.