High-grade RTV silicone-based rubber. The normal set time is 24 hours. A truly superior product to use when molding or casting a highly detailed item. Mix 1 – 10 by weight until consistent in color. Fast set catalyst will shorten set time down to a couple of hours if desired. Non-inhibited by sulfur, sodium, or epoxies. Also, will be set up against oil clay. No release is required either when making the mold or casting parts.