Preservation masters and access copies

Define the role of each file

A preservation master is the version selected for long-term retention with its supporting information. An access copy is made for a particular use, such as emailing a photograph or reading a transcript. The distinction is a management decision, not a magic property of a file extension.

For a born-digital file, retain the original bitstream when possible. Converting a small JPEG to TIFF does not recover lost detail. If you create a new version for continued access, document its relationship to the original.

Keep editing separate

Create a protected originals directory and a working directory for edits. Export access copies from working files. Use clear names or inventory fields for role and version. Never rely only on which folder happens to be open in an application.

A restoration may remove noise, scratches or silence that a researcher would want to inspect. Keep that derivative separately and describe what changed. Preserve project files and dependencies if the ability to revise the edit matters.

Test a small delivery set

Choose a representative photograph, document and recording. Open the retained version, export an access version, and verify that another reader can use the latter with an appropriate common application. Check orientation, legibility, duration and any subtitles or captions.

Document a recipe for the access copy: source identifier, tool, export date and changes. It should be possible to produce another access copy without treating the derivative as the only surviving source.

Keep all necessary parts

A project may require fonts, linked images, audio or sidecar metadata. A video may depend on companion files. Inventory those relationships before moving or renaming things.

Keep both master and access copies under the backup plan, but prioritize originals and unique work when resources are limited. A replaceable thumbnail and a unique recording have different recovery value.

Working checklist

Use this as a session checklist. Ticks are saved only in this browser; download a worksheet to keep a portable record.