Labels on discs having silver metallizations may therefore have a better appearance than discs having gold metallizations. Longevity of CD-R discs having gold metallizations has been widely examined. Comparable longevity data for silver discs has not been widely published. Manufacturers of silver discs may have evaluated the stability of the metal-dye interface. However, the extensive history that exists for gold has not yet been established for silver discs, and negative surprises are always possible.
Sulfur is a common pollutant, and is known to react with silver.
Even though the silver layer is protected by a thin coating on the label surface, pollutants could pass through very small cracks or scratches in the protective layer. The result could be loss of data. Some manufacturers have evaluated the results of exposure to sulfur dioxide and may be willing to share their results. Users of CD-R discs that use a silver reflective layer should request longevity information from the manufacturer. Otherwise, silver discs seem to perform at quality levels that equal or exceed those of CD-R discs that use gold metallization.