Acetate disc

An acetate disc (also known as a lacquer, test acetate, dubplate, or transcription disc) is a type of phonograph record generally used from the 1930s to the late 1950s for recording and broadcast purposes.

Lacquer-coated discs are used for the production of records. Unlike ordinary vinyl records, which are quickly formed from lumps of plastic by a mass-production molding process, a lacquer master or acetate (instantaneous record) is created by using a recording lathe to cut an audio-signal-modulated groove into its surface – a sequential operation requiring expensive, delicate equipment and expert skill for good results.

In addition to their use in the creation of masters, lacquers were widely used for many purposes before magnetic tape recorders became common, and in the modern era they are used by dance music DJs. They were used in radio broadcasting to archive live broadcasts, pre-record local programming, delay network feeds for broadcast at a later time, and provide programming "from home" on the Armed Forces Radio Network. They were used extensively in Jamaica by sound system operators in the late 1940s and 1950s. Acetates were often used as "demos" of new recordings by artists and record labels. Some acetates are highly prized for their rarity, especially when they contain unpublished material.