What Is CD-R Extraction?

CD-R discs are recordable optical media that use a recording layer rather than the physically pressed structure of a commercial CD. Their ageing characteristics can make timely extraction important.

Pressed CD versus CD-R

The National Archives notes that recordable optical media can be less reliable over time because the recording layer is susceptible to degradation.

CD-R ageing

Inspect the disc before extraction and avoid unnecessary handling of the data surface. Readable media should be copied into controlled storage as soon as practical.

Reading difficult discs

Where a CD-R contains important data, preserve both extracted files and relevant disc-level information. A complete image may be useful where the original structure matters.

Verification

Do not assume that a disc which mounts successfully has been recovered completely. Verification should identify missing or unreadable sectors.

Preservation after extraction

Record extraction results, errors, checksums and any unusual disc behaviour.

Reference guidance: This article is informed by optical-media preservation guidance from the U.S. National Archives and the Library of Congress Recommended Formats Statement. Where appropriate, the article distinguishes preservation guidance from practical extraction procedures.