Increasingly manufacturers are using polyurethane instead of silicone for making molds or flexible inserts for tooling. Soft shore polyurethane research and development has advanced significantly over the last few years, and similar performance characteristics to silicone can now be achieved. Polyurethane components are lower in viscosity than those of silicone, thereby decreasing the time needed to process the system and making polyurethane easier to work with in general. With the appropriate release agent, polyurethane molds will last as long or longer than those made of silicone. And with an average cost less than half the price of silicone, polyurethane is increasingly becoming the material of choice for flexible tooling.