What is the best type of mold for mask making?
I would like to say that there was only one answer to this question but latex Mask Makers actually have several choices all of which are gypsum based products. The main factors when choosing the mold compound are 1) mold production time 2) production casting time 3) mold life and 4) casting requirements. The type of sculpture that your create and the number of castings that are required will nearly always dictate which compound you select. In my experience the two best choices for mask molds are Ultra Cal 30 (UC30) and White Hydrocal ((WH). Both are plaster like products made by U.S. Gypsum Corporation. Each has its pro’s and con’s relative to the four factors mentioned above. #1 Casting Plaster and Pottery Plaster can also be used as substitute for White Hydrocal but the strength is not nearly as good. Be sure not to use any product labeled Plaster of Paris though as it is far too weak for mask molds. Georgia Pacific makes a product called Densite K-25 Industrial Tooling Gypsum which
