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: 1957? - 1960?

MG-20285A-1  M1  MSI  A Matrix inscription of Mercury MG-20285 Side-A This inscription may indicate this platter was pressed using the first mother or stamper (A) from the first-cut lacquer (1 or M1).

From circa 1957, Mercury Popular Series and EmArcy mono issues were pressed at another plant (highly probably MGM plant - still investigating), while Living Presence series and EmArcy Stereo issues were still pressed at Indy plant.

The matrix information was inscribed type. And as seen on very early type, this type also has such stamps/inscription as “M”, “A” or something like that.

This type can be found on such series as

• MG-20000 Series Monaural (Popular, 12-inch LP, around MG-20270 and beyond)
• MG-36000 Series Monaural (EmArcy Jazz, 12-inch LP, around MG-36104 and beyond)

MG36115A-1  M  MSI  B Matrix inscription of Mercury MG-36115 Side-A This inscription may indicate this platter was pressed using the second mother or stamper (B) from the first-cut lacquer (1 or M).

SR-60054-A  FR-1  B3  I  FF Matrix inscription of Mercury SR-60054 Side-A This inscription/imprint may indicate this platter was pressed using the third stamper (3) from the second mother (B) from the first-cut lacquer (FR-1). This is an unusual case - handwritten matrix with RCA Victor Indianapolis indicator. Probably there were some unknown reason to press at Indy plant using the lacquer cut not for the Indy plant.