Matrix system · Columbia Records
Columbia vinyl matrix numbers.
What the mark really means.
A Columbia runout often looks orderly enough to solve at a glance: a stamped prefix, a five-digit master number, then a cut suffix. The useful part is knowing what each block identifies. XLP and XSM describe the master series and format; the suffix points to a lacquer cut. Neither one, by itself, tells you the complete pressing history.
01
The quick decode
XLPMatrixA Columbia 12-inch mono LP master-series prefix.
Where: Usually machine-stamped before the master number in the dead wax.
Do not assume: It identifies format and master series, not a first pressing by itself.
XSMMatrixA Columbia 12-inch stereo LP master-series prefix.
Where: Usually machine-stamped before the master number in the dead wax.
Do not assume: A stereo prefix does not date the lacquer or identify the pressing plant alone.
-1A / -1BMatrixA Columbia lacquer or cut suffix attached to the side's master number.
Where: At the end of the stamped matrix, for example XSM 123456-1A.
Do not assume: Earlier-looking letters are useful evidence, but rejected cuts, parallel lacquers, and later metal use make a simple A-equals-first rule unreliable.
02
How to read it in the full runout
- Start with the prefix: XLP usually points to a 12-inch mono LP master; XSM to stereo.
- Treat the central number as the identity of that recorded side, not the album catalog number.
- Read the final dash suffix as the lacquer/cut clue and copy every character exactly.
- Compare both sides. Mixed suffixes are normal and can reflect different cutting histories.
03
What this mark does not prove
A runout clue answers one manufacturing question. A pressing identity comes from several clues agreeing with one another.
- Calling any -1A side a first pressing without checking the label design and release date.
- Assuming side one and side two must carry matching cut letters.
- Confusing the matrix master number with the CL, CS, or later album catalog number.
04
Check your copy in four passes
- Photograph both labels and confirm the label era matches the album's release window.
- Copy the complete stamped runout from each side, including the prefix and suffix.
- Match the mono or stereo format to the jacket and catalog prefix.
- Compare the full combination—not one suffix—with a documented copy of the same title.
05
Put the mark back on the record
1959 · Columbia six-eye
Charles Mingus — Mingus Ah Um
Check the complete pressing1959 · Columbia six-eye
Dave Brubeck Quartet — Time Out
Check the complete pressing1970 · Columbia 360 Sound
Miles Davis — Bitches Brew
Check the complete pressing1965 · Columbia two-eye
Bob Dylan — Highway 61 Revisited
Check the complete pressing- Columbia six-eye label guide
Match the matrix to Columbia's late-1950s and early-1960s label family.
- Columbia two-eye label guide
Compare 1960s label wording with the stamped matrix in the dead wax.
- Kind of Blue first-press guide
See how label, matrix, format, and the famous speed issue work together.
Sources
Reference trail
Runout conventions are label- and era-specific. These references support the decoding above; title-level identification still requires the complete copy.
Keep checking the shelf
Decode another part of the runout.
A single dead-wax string can contain a master, engineer, lacquer, and plant.
Pressing plant · Atlantic family
Atlantic pressing-plant codes
Decode Atlantic label and runout suffixes including PR, MO, SP, and RI, then separate the pressing plant from the lacquer-cutting engineer.
Check this pressing
Pressing plant · Capitol Records
Capitol pressing-plant symbols
Identify Capitol records pressed in Scranton, Los Angeles, Jacksonville, or Winchester from the IAM triangle, star, zero, and rifle-like runout symbols.
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Mastering and plant · Blue Note
Blue Note RVG and Plastylite ear
Tell Blue Note's RVG or VAN GELDER mastering mark from the Plastylite ear pressing-plant mark, and learn why one can survive without the other.
Check this pressingA few questions
The ones that come up.
XLP is a Columbia master-series prefix used for 12-inch mono LP sides. It helps identify the format and internal master series, but does not prove that the copy is a first pressing.
XSM is a Columbia master-series prefix associated with 12-inch stereo LP sides. Read it with the master number, cut suffix, label design, catalog, and jacket.
Not automatically. It usually identifies an early lacquer in Columbia's cutting sequence, but parallel cuts, rejected lacquers, multiple plants, and later use of metal parts mean the entire pressing must be checked.
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