Compression molding is among the oldest materials processing techniques. For plastics, it was one of the first industrial methods, and is also known as matched die molding. The basic process consists of heating a thermoset resin, under severe pressure, within a closed mold cavity until the resin cures through a chemical reaction of cross-linking polymeric chains. Under pressure, the resin liquefies and flows, taking the shape of the mold cavity, and then hardens into the desired product. Once sufficiently cooled and strong, the part is removed from the mold. The curing reaction continues while cooling to ambient (room) conditions. Common resins include phenolic (phenol-formaldehyde), urea-formaldehyde, melamine-formaldehyde, epoxy, polyester, vinyl ester, silicone, alkyds, diallyl phthalate (allyls), and various rubbers and elastomers. This process is suitable for a wide range of industrial, commercial, and consumer parts and products ranging from very small to large automobile body panels.