Molds should be stored indoors with no exposure to sunlight, in a position that does not distort the mold, and at room temperature. If it is a blanket mold store it in the mother mold (shell) with a cast part inside if possible. If the mother mold or cast part are made of a porous material like plaster, gypsum, or concrete, be sure to seal them with a paint or sealer. A porous material will draw the fluids out of the rubber and cause shrinkage and distortion over time.