A record press is a machine for manufacturing vinyl records. It is essentially a hydraulic press fitted with thin nickel-plated stampers which are negative impressions of a master disc. Labels and a pre-heated vinyl patty (or "biscuit") are placed in a heated mold cavity. Two stampers are used, one for each of side of the disc. The record press closes under a pressure of about 150 tons. The process of compression molding forces the hot vinyl to fill the grooves in the stampers, and take the form of the finished record.