This product of the mastering process involves a large glass disc, duly prepared and coated with a recording layer--usually Photo resist. After recording, the glass master goes through a special chemical process (ak into development), and is then metallized. The metallized glass master, also referred to as the 'positive,' is submitted to electroforming, to produce the metallic (usually nickel) master--which is necessary for producing the stampers for the injection molding machines.
Part of the CD and DVD disc manufacturing process that uses a laser (which is modulated by the data to be stored on the disc) to expose areas of a photo-resist layer on a glass disc, where the final pits are required. These areas are then developed and the photo resist layer metallised so that stampers can be grown by electroforming usin this metal layer. The stampers are then used for moulding CD and DVD discs.