The Preservation Stack
Preservation master
A preservation master is the highest-quality, standards-conformant copy of a recording — the file from which every other copy derives, held with complete metadata and rights documentation.
The master is defined by what it is not: it is not the file that gets emailed, screened, uploaded, or cut into a trailer. Those are access copies — derivatives produced from the master for viewing, study, or promotion. The separation is the point. Every generation of editing, compression, or format conversion loses information; the master exists so that loss is never inherited. Whatever happens to the copies, there is one lineage-zero object whose quality is known and whose history is verified.
Holding a master is an active discipline rather than a storage decision. Audiovisual preservation practice — set out most fully in the IASA technical guidelines — expects formats chosen for longevity rather than convenience; integrity verified by checksum from camera or transfer onward, so silent corruption cannot pass unnoticed; redundancy across carriers and locations; and complete metadata, so the file remains findable and attributable.
Two failure modes account for most lost masters. The first is conflation: the highest-quality file doubles as the working copy until re-exports quietly replace it. The second is legal: a technically perfect master recorded without documented permissions cannot be shown, studied, or broadcast — preserved in every sense except the ones that matter.
IASA TC-04, Guidelines on the Production and Preservation of Digital Audio Objects · IASA TC-06, Guidelines for the Preservation of Video Recordings.
First published 18 July 2026 · Revision 1 · Substantive changes to this entry are dated here.