Here is a rare piece, which offers great insight into the production process of the Micro line. This silicone mold, referred to as a room temperature vulcanizing rubber mold in the toy trade, was created from the original wax sculpting of the 4-up. To create a 4-up hardcopy the two mold halves are placed together and liquid urethane is poured into an open cavity located in the mold bottom. Once the resin solidifies, the mold halves are separated and the 4-up is removed. After removal from the mold, the bottom of the 4-up must be sanded down to remove what is referred to as a "pour stem". The pour stem coincides with the area where liquid resin is poured into the mold.