Why do re-writables go bad?

I primarily use write-once disks; therefore, I don’t use too many DVD+RWs or CD-RWs so my experience with re-writable disks is limited. I was wondering why a re-writable disk goes bad after a certain number of burns. I have heard that DVD+RWs, DVD-RWs, and CD-Rs can last up to 1000 burns while DVD-RAM can last up to 100,000 burns. That gets me to wonder what makes a DVD-RAM disk better and what makes the others worse.

Why does a re-writable disk go bad? And - once they are bad is there any way to restore them, or are they permanently trash?


Bob Shem

rw is phase change which means the dye changes from a crystiline reflective structure to a non reflective which is how it mimics the holes that are burned in the dyes of a write once disc. the discs loose their ability to change back and forth with age. i don’t know if you have noticed but RW discs rarely sell so they are probably n the shelf for YEARS longer than the write once media. in my opinion that explains somewhat the shortness of their life. the other part would be that temp changes and exposure to light will also cause phase changes. in my house an rw disc will rarely be able to be read after 6 months. iw ould not ever consider them for archival use but would use them to move a file from one computer to another.