-edible zone-

  (hint: click thumbnail for full size image)

  above: a yellow on black Parlophone label from 1965


PMC1230 A Hard Day's Night, Mono Mix 1st Pressing

PMC1267 Rubber Soul; Mono Mix 2nd Pressing

PCS 7027 Sgt. Peppers; Stereo Mix 1st Pressing

PMC 7027 Sgt. Peppers; Mono Mix 1st Pressing

PMC 7009 Revolver: Mono Mix 2nd Pressing

   Decoding the UK EMI matrix:

At 6 o clock is the matrix number with a dash number. In this case it is XEX 638-1
Dash 1 indicates the 1st lacquer made. -2 would be the second, etc.

At 9 o clock is the mother number. In this case it is Mother # 8

At 3 o clock is the stamper code. The code works like this:

GRAMOPHLTD

 1 2 3 4 5 6 7 8 9 0

The letter above is code for the corresponding number below. Example: the stamper code is "MDP" in the record below. This corresponds to the numbers M = 4. D = 0. P = 6. Stamper is #406 

   PMC Matrix GIF

Example above: side 2 was made by the 1st lacquer, the 8th mother and pressed by the 406th stamper. Perhaps the record company could anticipate total sales volume and, up front, they might produce all the needed lacquers, mothers and stampers. Or perhaps at a later date, the record company would need to produce additional lacquers and mothers in order to meet customer demand for the product. In the case of The Beatles, millions of LPs were typically sold within the early weeks of production and, during the years after that, millions more were produced as 2nd, 3rd and later pressings.



How records are / were made, very briefly.
An audio recording was taken of a performance, likely on magnetic tape. A "master" tape.
A lacquer / acetate is generated when the cutting lathe transcribes the performance from the master tape onto the acetate disk.
The acetate/lacquer is given a thin coating of silver, then a layer of nickel, then copper.
The metal coating, once peeled off the acetate, is called the Master. The Master taken from the acetate is the reverse profile of it and has ridges instead of grooves. In order to obtain a playable mold, the master is used to make another mold, called the "mother"
Stampers, molded from "mothers" are used to press heated vinyl into the final form.