I'd probably start with this which describes the m-disc, which is made for longterm cold storage. If you check out the wiki for bluray it talks about how some forms use organic methods of writing. Check out Types > Bluray Disc recordable section:

On September 18, 2007, Pioneer and Mitsubishi codeveloped BD-R LTH ("Low to High" in groove recording), which features an organic dye recording layer that can be manufactured by modifying existing CD-R and DVD-R production equipment, significantly reducing manufacturing costs.

In any case, optical discs are not really "stamped" it is generally burned using a type of laser, and usually on to an organic dye, though that is what the posters your replying to are talking about:

An optical disk recorder encodes (also known as burning, since the dye layer is permanently burned) data onto a recordable CD-R, DVD-R, DVD+R, or BD-R disc (called a blank) by selectively heating (burning) parts of an organic dye layer with a laser.

edit: also worth mentioning – my favorite podcast the Accidental Tech Podcast (which, be forewarned is Apple-centric) released an ep not too long ago discussing this. It's part of their post-show on this ep and they use chapter markers, so you can skip basically right to it if you have a half decent podcast player. It's not intended as an explainer video or anything, but having not thought about optical discs in quite a while it does serve as a half decent refresher.