The cover can lie. The same catalogue number can sit on a 1973 original and on last year's repress, and two seemingly identical copies can differ by hundreds in value. The one place where the record itself tells you exactly which pressing it is: the runout — the smooth band between the last groove and the label. That's where the matrix numbers live, and once you can read them you can identify a pressing more reliably than any sleeve comparison.
What the runout is
The runout (also called the deadwax) is the ungrooved surface closest to the label. When a record is mastered, codes are etched or stamped into the lacquer that becomes the template for the pressing tools — and those codes carry over to every copy pressed from them. That makes the runout a kind of birth certificate: it tells you which master cut, which pressing plant and sometimes which individual stamper your copy came from.
Finding and reading the codes
Hold the record at an angle to a strong, directed light source and rotate it slowly — the etched characters catch the light. Some codes are machine-stamped and tiny; a loupe makes a real difference. Write down everything you see, from both sides: side A and side B carry their own codes.
What you'll typically find:
- Matrix number — the base code, often the catalogue number plus a side marker, e.g.
ABC-123-A. - Take or lacquer number — a digit or letter after the matrix number showing which cut was used (
-1,-2,A//1and so on). Low numbers mean an early cut — not automatically a first pressing. - Pressing plant mark — many plants stamped their own symbol or letter code, so one edition can exist with several different plant marks.
- The mastering engineer's signature — some engineers signed their work in the wax. Famous examples include "RL" (Robert Ludwig) on early Led Zeppelin II pressings and British engineer George Peckham's "A Porky Prime Cut". A signature like that can affect value on its own.
- Mother and stamper codes — numbers or letters showing which generation of pressing tools was used. The earlier, the closer to the original cut.
Why it matters for value
Two pressings of the same album can trade at completely different prices. A first pressing with a sought-after cut can be the copy collectors chase, while a later pressing from the same decade looks identical on the sleeve and sells for a fraction. The runout is often the only reliable dividing line. It also protects you the other way round: a record sold as an "original" with the wrong matrix codes is either misdescribed or deliberately mislabelled — worth knowing before you pay original-pressing money.
Using the codes on Discogs
Discogs lists runout codes for most editions in the "Matrix / Runout" field on the release page. The workflow is simple: copy your codes, look up the album, and compare against each edition's matrix field until you find the one that matches. The codes should match on both sides, and minor variations (stamper numbers) can differ between copies of the same edition — it's the matrix number and cut codes that identify the edition, not every last character.
The Rekord app has this built in: on a scanned record's result page, open "Exact pressing" and type in the matrix number, and the pressing is looked up directly with market data for that specific edition.
Common pitfalls
- Don't confuse catalogue number with matrix number. The catalogue number appears on sleeve and label and is shared by many pressings; the matrix number sits in the wax and separates editions.
- A low cut number is not proof of a first pressing. A
-1cut can have been used across years of pressings. Always combine with label and sleeve details. - Represses can reuse old tooling. Some new pressings are made from original stampers and carry old codes — check the label typography, rights text and barcode too.
- Copy exactly. A single character can separate two editions. Note symbols, underscores and handwritten marks as well.
Quick checklist
- Aim a strong lamp at a low angle across the surface.
- Read the runout on both sides, ideally with a loupe.
- Copy every code exactly, symbols included.
- Compare against the "Matrix / Runout" fields on Discogs — or type the code into Rekord's pressing search.
- Confirm with label and sleeve before drawing conclusions about value.
The runout is the closest thing a vinyl record has to a fingerprint. A few minutes with a lamp and a loupe gives you surer answers than hours of sleeve comparison.