All of the CDs in my old collection are fine, but I’ve had major problems with my DVD collection. I haven’t spent any time trying to figure it out, but it looks like some kind of unusual mold that I’ve never seen or some kind of deterioration of the substrate occurred inside some of the discs and they became completely unplayable. Attempts at cleaning completely failed to solve the problem. Is there really a major difference between DVD and CD manufacturing on a commercial level?
As explained in the article DVDs are made by sandwiching the dye and reflective layers between two polycarbonate layers, which are then glued together. The adhesive used is sometimes prone to failure, causing delamination of the disc (this can happen with pressed DVDs as well, I have a few Xbox 360 games that became unreadable due to moisture getting between the layers). CDs do not suffer from this issue as the data layer is placed directly under the label, with no need for an intermediate polycarbonate layer.
