Gold Archival CD/DVD Media
The use of the precious metal gold is implemented for optical media with the intent of extending longevity, especially for archival purposes. Backup storage is essential for home, commercial and industrial purposes, but the average disc may not provide the reliability and durability of a sustainable shelf life.
Standard CDs, DVDs and Blu-rays in the ROM, R, and RW/RE formats employ an aluminum alloyed reflective layer for the data to be read by the drive's laser. Due to the properties of aluminum, it is highly susceptible to corrosion which can therefore shorten the lifespan of the disc. Consequently, 24 carat gold and occasionally pure silver replaces aluminum for some manufacturer discs to combat corrosion.
Aluminum disc layers can start to rust immediately after coming into contact with air. To a lesser extent, silver will oxidize, but at a slower rate-its weakness for tarnishing is its contact with sulfurous materials. Traditionally, a protective lacquer coating is meant to shield aluminum and silver alloyed layers and well as the disc's subsequent layers from environmental factors, but it's not always impenetrable. Corrosion of these discs will still occur even with the use of a hard lacquer.
The use of gold in a disc's reflective layers provides manufacturers with a significant upgrade in the quality and shelf life of CDs, DVDs and Blu-rays. Pure gold does not oxidize in air or water as well as in most other elements it could encounter under normal circumstances. Therefore, gold maintains its luster for reflective purposes over a longer period of time.
For example, one manufacturer tested that gold-based reflective layers can endure a greater dose of prolonged UV, humidity and heat exposure in conjunction with a high grade of Phthalocyanine dye. This manufacturer calculated and claimed the disc's lifespan to be at approximately 300 years, which defeats the average 25-100 year lifespan of aluminum layered discs.
Gold archival discs are available for CD-R, DVD-R and BD-R formats. The quality and durability is reflected in the price of the media. Currently, gold discs are more than quadruple the price of their aluminum layered counterparts. It should be noted however that gold discs are not any stronger than standard manufacturer discs when encountering the impact of physical damage.
- CD/DVD Degradation
- Gold Discs Explained
- Lifetime of Kodak CD Media
- Lifetime of TDK CD Media
- Media Longevity
- Recordable Media Quality and Longevity
- Special Report: Media Longevity