Ray parenchyma cell piece mold, circa 1910s-1970s

Piece molds used to make a ray parenchyma cell for an exhibit, possibly between the 1910s and the 1970s.

Piece molds can be made of two or more pieces. The two or more pieces of the mold form a receptacle into which wax is poured through a funnel-like gate cut in the plaster. For cactus and larger specimens wax cloth is not used, instead hot wax is poured directly in the mold, which had to be previously placed in hot water to expel air from the plaster. Many wires were used not only as a midrib but as additional support for the heavy mass of wax.