4X ZeroShrink™ is made in America and the only zero shrink heat cure mold rubber of any kind available today. This rubber provides results normally only seen from a metal mold. 2007 MJSA innovation award winner. Works well with all mold making applications especially those that require exact replication. Because of the greater density, finished molds resist internal wax deflection (less flash).
This rubber cures at 250oF 115oC so make sure your RP material can handle that temperature if you choose this rubber. It is much cooler than the 350oF of regular silicone rubber but 250oF is bumping the ceiling on many RP materials top temp.