The BD-R write-once type is based on a completely new concept for the recording layer utilizing a two-layer structure composed of silicon (Si) and copper alloy (Cu) inorganic materials. When heated by the recording laser beam, these melt and the Si and Cu alloy become a composite forming recording marks. Because the material is inorganic, it is not affected by light, thus realizing a disc with outstandingly high reliability in terms of archivability.
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Write-once recordable DVD-R/DVD+R media (as well as CD-R media) all uses synthetic organic based dyes – usually azoic dyes (metallized azo chelates or azo metal chelate). Some of them are based on other synthetic organics, such as cyanine, dipyrrometheme or oxonol.
From what I recall, only self-burnt CD’s and DVD’s degrade quickly, while self-burnt blu-rays last significantly longer, even if not m-discs.
Yep! Quote from digitalfaq
And another quote from the same source