AIUI, it’s a chemical process that applied to certain discs that had a silver substrate - they effectively tarnished. I also have a few discs that have the pinholes you describe, but I think this is a different thing - they were there from the beginning on mine. And the neat thing about CDs is that the pinholes didn’t make any difference when I ripped or played those discs - the error-correction algorithms that CD systems use are pretty amazing.
Yep, same here. But I’m still impressed by how many 25 year-old CD-Rs I have are still readable - only one or two out of stacks and stacks of them have had the dye degrade.
