Dvd disc issue problem.

[JayJay315]

Hey, i have a question about Dvd Discs. I noticed on dvd's from all company's, my old ones and even new ones that i just bought, if you hold them to an artificial light they have grey discolouring on the play side, (pictures on google under disc discouloring) but it's not a defect that affects the movie but anyone know what this is? I cannot seem to find any answers about it. Thanks!

 

[CountMike]

It's substrate data is recorded on. Factory CD/DVDs are printed on metal substrate (which is actually on other side of plastic disk) while writable disks have metal plus some organic substrate that changes composition of material when hit with laser beam of proper frequency. In either case, there are microscopic pits that signify bit 1. Because of that it appears as flat and not shiny.