Rubber Mold. A flexible mold for casting sculpture in-the- round or bas-reliefs; it is ideal for models with undercuts. Such molds were formerly made of gelatin (with alum for surface hardening); more recently of PVC, latex, or more popularly, silicone rubber. Hence what used to be a gelatin mold, or more recently a flexible mold, is now made by rubber mold.
excerpted with permission from
An Encyclopedia of Coin and Medal Technology
For Artists, Makers, Collectors and Curators
COMPILED AND WRITTEN BY D. WAYNE JOHNSON
Roger W. Burdette, Editor