Editing Data degradation (section)

====Optical media====
[[Optical storage|Optical media]] such as [[CD-R]], [[DVD-R]] and [[BD-R]], may experience data decay from the [[disc rot|breakdown]] of the storage medium. This can be mitigated by storing discs in a dark, cool, low humidity location. "Archival quality" discs are available with an extended lifetime, but are still not permanent. However, [[Optical disc#Surface error scanning|data integrity scanning]] that measures the rates of various types of errors is able to predict data decay on optical media well ahead of uncorrectable data loss occurring.<ref name="qpx-g"/>

Both the disc dye and the disc backing layer are potentially susceptible to breakdown. Early cyanine-based dyes used in CD-R were notorious for their lack of UV stability. Early CDs also suffered from [[CD bronzing]], and is related to a combination of bad lacquer material and failure of the aluminum reflection layer.<ref name="IASA_1997"/> Later discs use more stable dyes or forgo them for an inorganic mixture. The aluminum layer is also commonly swapped out for gold or silver alloy.