Frequently Asked Questions: Preservation

Although optical disks may be used for access or to temporarily store media, they are not an effective solution for long-term storage of important files. CDs and DVDs are easily scratched or smudged, which may cause read errors or prevent playback. Additionally, the organic dyes used in optical discs will eventually degrade, making them unreadable. 

Maximize chances of file stability by:

• Use a reliable brand of optical disc
• Use reliable writing software
• Avoid writing multiple sessions to a disc -- to maximize use of disc, gather files close to the full storage capacity of the disc, then write in a single session
• Test that the disc is readable on two different machines
• Always have a backup

Tests indicate that both the dye material and the reflection layer affect the durability of the optical storage medium and that the gold colored optical discs are the most durable in sound storage conditions. For more information, refer to the CD Longevity Research currently underway at the Library of Congress.  Other studies include the article CD and DVD Longevity: How Long Will They Last by Andy Marken.