Molds are produced by providing a master of relatively inexpensive material, preferably wood. The wood is coated with a material which will have the texture and dimensions of the end product to be produced. The coating material must be inert to a plating solution and must be conductive to permit deposition of the plating solution thereon. The master thus produced is electroformed to provide a metallic envelope of copper, nickel, or mixtures thereof thereabout. A box, open at one end, including a rear plate and peripheral frame members is provided for each contoured wall. Wax rods are mounted on the electroformed envelope. The wax rods communicate with the ends of metal tubing. A layer of silicone rubber or similar material is applied over the wax rods and the ends of the tubing. The wax rods are melted thus forming heat transfer conduits. An insulating foundation of polymethane is foamed in place between the rear face of the boxes and the rear face of the contoured walls. Thereafter, the electroformed envelope is severed about its periphery and the mold halves are removed for use with low pressure injection molding apparatus. Floating connectors associate the contoured walls of the mold with the frame members of the box so that relative thermal expansion of the box independently of the contoured walls is possible.