Vinyl record Matrix Numbers and messages in the runout groove.

The world of vinyl records is filled with mystery and one of the most intriguing elements for collectors and enthusiasts is the engraving found on the dead wax or runout groove of a record, often called the matrix number. These tiny, sometimes cryptic markings have sparked all kinds of theories, some of which verge on myth. If you’ve ever wondered what these numbers actually mean and perhaps more importantly, what they don’t, this post aims to shed light on the subject.

What Is a Matrix Number

Matrix numbers are alphanumeric codes found in the dead wax (the smooth area between the last track and the label) of a vinyl record. These engravings can serve as a trail of breadcrumbs that leads us back to the record’s origins. But before we dive into what they tell us, let’s explore when and how these markings are applied.

When Does Engraving Process Happen?

Engravings can happen at different stages of the vinyl record manufacturing process. Generally, the initial matrix number is inscribed during the cutting process, when the record’s master is being made. This master could be either a lacquer or a Direct Metal Master (DMM), and the cutting engineer is usually the one responsible for this initial engraving. Typically, this number matches the catalog number of the record with an aditional A or B to indicate the sides and a code for the cutting room.

The engravings added at the cutting stage however are not resticted to the alphanumeric matrix numbers sometimes, artists will request special messages or hidden symbols to be etched into the wax, adding a layer of personalisation to the record. Cutting engineers frequently also mark the master with their initials or a unique symbol much as an artis will sign their work. These extra engravings are far from standardised, there are no strict rules, and it’s largely up to the engineer or the record label to decide what gets inscribed.

Engraving matrix numbers at the Pressing Plant?

Once the master (either lacquer or DMM) reaches the pressing plant, it undergoes a galvanic process to create the plates for the pressing machine. At this stage, pressing plants will engrave their own identification numbers into the record. These numbers are often additional matrix codes and their complexity can vary however they are generally used to keep track of the pressing process. The plates used to press a record can only be used a finite number of times before they become worn and new ones need to be generated.

The exact format of these numbers differs from one pressing plant to another, and just like the initial engravings, these too are subject to the client’s preference. If the record label doesn’t want to reveal where the record was pressed, they might ask the pressing plant to omit this number altogether.

Debunking the Myths: What Matrix Numbers Don’t Reveal

While matrix numbers can tell us a lot about a record’s production journey, there are many things they don’t reveal, despite common misconceptions. For instance:

They don’t always indicate where the record was pressed.
If a pressing was done at multiple plants to meet high demand, there may be no reference to the plant at all.

They don’t tell you about the audio quality.
Although some collectors believe that certain pressing plants or cutting engineers produce better-sounding records, the matrix number itself doesn’t give you an immediate clue about this.  

They don’t provide complete transparency.
The decision to engrave certain information is often up to the client (the record label), and many details may be omitted by choice. In some cases, pressing tools are created by third-party manufacturers and sent to multiple plants, making it even harder to track down exact origins.

The Art and Mystery of Engraving Vinyl Records

One fascinating aspect of matrix numbers is that they’re almost always engraved by hand. Even when the numbers appear stamped, they’re generally applied using a tool called a pantograph, a device that allows a technician to trace a letter or number with a stylus, which is then etched into the record. This method, also known as the stork’s beak, adds a handcrafted element to vinyl production. It’s a meticulous process, yet another detail that makes vinyl records feel like works of art.

Famous messages engraved on records

There are many famous messages or signatures engraved on records. One of the best know is from legendary mastering engineer George Peckham, who signed off many of the thousands of records he cut from the ’60s onwards with his nickname “Porky”, or “A Porky Prime Cut”. Occasionally he’d respond to lyrics on records with witty asides, while on others, like Elvis Costello’s 1978 album, This Year’s Model, he’d kick-start frenzied competitions by inscribing telephone numbers that fans could call to win prizes. On Primal Scream’s 1990 EP Loaded, Porky cut the words “FREE SLY STONE!” onto one side and “FREE JAMES BROWN!” onto the other.

Look closely at your collection to see if you can spot any messages!

Final Thoughts: Unraveling the Mystery of the runout groove

Matrix numbers can tell us a great deal about a record’s history—from who cut the master to where it was pressed. However, it’s important to remember that not all information is revealed in these tiny engravings. In some cases, what’s left out is just as significant as what’s included. Still, for collectors, the hunt for these numbers and the stories they tell can be a thrilling part of the vinyl experience.

So next time you pull out a vinyl record and inspect the runout groove, remember that while matrix numbers hold clues, they don’t tell the whole story and that’s part of what makes them so intriguing!