Molding_melissa_2. Mould making for ceramics. The secret of successful slip casting reproduction lies in the proper making of plaster moulds. As pointed out in the part on slip casting, moulds are made of plaster of Paris. It is well, therefore, that we discuss plaster of Paris, what it is, and how it is handled to obtain the best results. Plaster of Paris Plaster of Paris is one form of gypsum-calcium sulphate in chemical combination with water-a common mineral existing in several forms, which was in ancient times and still is employed to make plaster of various kinds. Pure gypsum is white and relatively soft. The name plaster of Paris derives from the quarries at Montmarte, near Paris, France, where natural gypsum was extensively mined.
Plaster of Paris is readily obtainable at any art or ceramic supply house and is quite inexpensive. When plaster of Paris powder is first mixed with the proper proportion of water, it becomes a soft plastic mass, which can be moulded, or cast in various shapes. General Information Lesson VIII Part 1. resin casting Translate.