Zero-D™ mold rubber is ideal for the most delicate patterns and for hardcarving waxes and rapid prototype resin models. It is flexible and tear-resistant. 4X ZeroShrink™ is the only heat-curable mold rubber available that literally delivers a shrink percentage of zero. Before curing, it is pliable enough to reproduce masters of all types of jewelry items-- from simple to complex. After vulcanization, with four times the tear strength of comparable products, molds have enough firmness to resist internal deformation, producing patterns with a sharpness of detail that rivals metal molds. No special temperature is required; cured at 250°F, a 3/4" mold can be ready in 15 minutes.