Mercury Matrix Number Variations

A “Matrix Number”, stamped (or inscribed) information placed between the last groove and the label, is always there, to indicate record number, mother stamper, and pressing plant.

With matrix number type, we can surmise the era when each platter is pressed. And Label variations also used for each vinyl also helps a lot to guess the pressed era.

Please note, that the variations on this site does not cover all known to exist: there are so many exceptions. So please understand the variations on this site are basic frameworks to identify famous patterns.

Matrix Number Variations: 1961? - 1967?

SR-90310A RFR-1  P17  FF Matrix inscription of Mercury SR-90310 Side-A This inscription may indicate this platter was pressed using the first-cut lacquer (RFR-1). However, there are no mother/stamper indications. Another inscription P17 may be a certain indication by George Piros himself, but I don't know what it means.

Like other series, Living Presence series' pressing was moved to the Richmond plant. Living Presence series has inscribed matrix information by George Piros himself. As many people have said, the transition from FR pressing to RFR pressing was probably made around SR-90260 (there are several exceptions though).

Matrix suffix are RFR followed by numbers. The last number may indicate the lacquer generation. Another inscription, such as P17, P13, P15, P126, CP25 are common, but I don't know what they actually mean.

This type doesn't have explicit mother/stamper numbers, but on some platters handwritten lines are added on the dead wax - this might represent stamper generations.

This type was used until middle-late 1960s, when George Piros ceased the relationship with Mercury. Later, even the Living Presence series was pressed with Richmond type imprinted stampers.

By the way, many collectors say that other matrix suffix such as CBFR (for Columbia's Bridgeport plant), CTFR (for Columbia's Terre Haute plant) and CCFR (for Columbia's Hollywood / Santa Maria plants) were for Columbia Record Club - Columbia requested “modest” cutting in order to make cheaper players can play through, then George Piros unwillingly cut as such. Sure enough, sound quality of such platters is inferior to RFR platters in general.

SR-90320A-RFR-1  P126 Matrix inscription of Mercury MG-20573 Side-A This inscription may indicate this platter was pressed using the first-cut lacquer (RFR-1). However, there are no mother/stamper indications. Another inscription P126 may be a certain indication by George Piros himself, but I don't know what it means.