Leaf squeeze molds, circa 1910-1970s

Four leaf-shaped squeeze convex molds and four concave molds, used to make plastic or wax casts for exhibits, possibly between the 1910s and 1970s.

Squeeze molds are sets of concave and convex molds. Concave molds are forms that work just like other molds in that the molding material is draped over their surface. With concave molds, the inside surface is exposed, while the outer face is in contact with the mold. This is opposite to that of convex molds, in which the mold is in contact with the interior side. These sets were attached to clamps for leaf-making.

To produce plastic leaves, a plastic sheet was put between the molds, and then clamped tightly under very hot water so that it could take the impression of the leaf. For wax leaves, after placing a thin sheet of cotton and wire for the leaf stem over the top of the mold, molten wax was poured over the cotton and then the squeeze molds were pressed over the hot wax. The wax was then cooled, and once the mold was removed the replica was ready for assembly.