The overwhelming majority of records manufactured have been of certain sizes (7, 10, or 12 inches), playback speeds (33⅓, 45, or 78 RPM), and appearance (round black discs). However, since the commercial adoption of the gramophone record, a wide variety of records have also been produced that do not fall into these categories, and they have served a variety of purposes.
European shellac records — In the first three decades of the twentieth century European companies including Pathé, Odeon, and Fonotipia made recordings in a variety of sizes, including 21 cm, 25 cm, 27 cm, 29 cm, 35 cm, and 50 cm (roughly 8½", 10", 11¾", 12", 14", and 20").
16" and 20" discs — Broadcastingstudios made use of 16" and 20" 78rpm acetate "transcriptions"; these were used for time-delay programs and for prerecorded broadcasts. These could provide up to 20 minutes of unbroken program material with very good fidelity (indistinguishable from live to casual, but not to critical listeners). Early classical LP recordings were in fact initially recorded on 20" 78-rpm acetates for later transfer to LP. 16" turntables are still seen in professional broadcast equipment, although it is probably very rare that any disk larger than 12" is ever played on them.<br/>
8" EPs. Mostly seen as Japanese pressed records in the......