STEP 2: Preparing the Rubber Mold The black rubber molds are purchased for home casting. The mold is two halves, the front and back of the toy soldier, or figure. Talcum powder is sprinkled onto both halves of the inside of the mold. The powder acts as a mold release, allowing the cast figure to be more readily separated from the mold when the metal cools. The powder also helps the metal flow to detailed areas of the casting. Once the powder is evenly spread, the two halves are clapped together to knock off the excess.