Mastering for vinyl: what pressing plants actually ask you to send

Streaming masters are built to be loud and bright and to play the same everywhere. A record is a physical groove cut into a lacquer, and the groove has limits a file does not. This guide uses the rules two record manufacturers publish themselves, checked on 26 Oct 2026: Disc Makers' guide to how much music fits on a record and Kindercore's guide to mastering for vinyl. Other plants and cutting engineers set their own limits, so take these as a baseline and ask yours.

If you are still working out whether a pressing pays for itself, start with our 300-copy break-even maths. For the digital side, see mastering at home and streaming loudness targets.

1. Fit the running time to the side

Disc Makers gives these lengths per side:

So a full LP is about 44 minutes in total. Longer sides can be cut, Disc Makers says, but bass is the main thing that eats space: more low end means wider groove modulation, so a long side forces the engineer to roll off bass, and in extreme cases to make the bass mono. Each gap between songs is a wider crossover groove that takes up the equivalent of about 20 seconds of music. More tracks on a side means less room. Disc Makers also says sides over 22 minutes cost more to master, because planning and recuts take longer.

Kindercore adds that 7-inch at 33 1/3 rpm is the most limited format, with lower level, more high-frequency loss and more distortion. It advises avoiding it unless there is no other option.

2. Put the bass in the middle

Kindercore's rule is blunt: all bass below 150 Hz must be centred. Phase problems in the low end "can cause a collapse of the groove, causing a skip". Check your low end in mono before you send anything. Wide stereo sub-bass from a synth patch or a stereo widener is the usual culprit.

3. Tame the top end

• Sibilance. Too much causes distortion on playback, and Kindercore says to fix it in the mix. De-essing at the cut is possible but is a patch.
• Highs. Kindercore says frequencies above 15 kHz "just cause distortion" and asks you not to boost above 10 kHz.
• Sequencing. Near the label the response is down about 3 dB at 15 kHz, according to Kindercore, so quiet songs and ballads belong on the inside and the loudest track should not close a side. Disc Makers says the same from the other end: bright, high-frequency songs work best early on a side.

4. Do not send the brick-walled master

Kindercore says not to clip waveforms, a trick from CD mastering that "will translate to distortion when cut". Heavy brick-wall limiting can also distort the cut. Re-cuts for distortion on audio with RMS over -10 cost extra, and a re-cut on clipped audio is fully billable. Send WAV or AIFF.

What we think

• Order two masters, and pay for it once. The rules above pull against a loud streaming master on every point: less limiting, centred bass, softer highs. Ask your mastering engineer for a separate vinyl master at the same booking. That is cheaper than a billable re-cut.
• Write the tracklist to the side, not the other way round. Most digital albums run past 44 minutes. Choose which songs go on the record before mastering rather than squeezing a 50-minute album and losing the bass that made it sound good. A cut track can go on a download card.
• Sequence for the groove. Keep the bright, dense singles near the outside edge and the sparse songs near the label. That is a creative choice as much as a technical one, and it is free.
• Treat any single plant's numbers as a floor, not a law. Disc Makers and Kindercore broadly agree, but their figures are their own house rules. Get your plant's spec sheet in writing before mastering starts.