abstract:The damage to the edge of this test acetate shows that the underlying material is aluminium, rather than the vinyl of a record sold at retail.An acetate disc, also known as a test acetate, dubplate (a term from Jamaican reggae culture, now also applied to individually recorded discs of solid plastic), lacquer (a technically correct term preferred by engineers in the recording industry), transcription disc (a special recording intended for, or made from, a radio broadcast) or instantaneous disc (because it can be played immediately after recording without any further processing), is a type of phonograph (gramophone) record, a mechanical sound storage medium, widely used from the 1930s to the late 1950s for recording and broadcast purposes and still in limited use today.