Consisting of pure natural gum rubber, Castaldo Gold Label Mold Rubber is soft and flexible, and is ideal for fine, delicate pieces and filigree. Experienced mold-makers know that this compound’s superior qualities can save them substantially on labor costs when used for difficult molds containing undercuts, where a stiffer mold would break delicate wax patterns. Rolls consist of 5 lbs. of rubber measuring 18" wide, 1⁄8" thick, and approximately 3-1/2 feet long. Provided in convenient fiberboard tubes.