Mudcat Café message #702212 The Mudcat Café TM
Thread #47161   Message #702212
Posted By: JohnInKansas
01-May-02 - 02:18 PM
Thread Name: TECH: How long do CDRs last?
Subject: RE: TECH: How long do CDRs last?
I've been looking for some believable info on this for a while now, with no particular success. It appears that "commercial" CDs are generally "pressed," so that the pits that contain the information are actually embedded into the parent material of the disk.

The laser used in CD-R recorders is relatively low-powered, so a more "delicate" recording layer is "pasted onto" the disk. Since the actual recording material is a separate part, deliberately made "vulnerable" to modification by the low-watt laser, it must certainly be more fragile than a single chunk of plastic.

Instructions with higher quality data CD-R disks warn against even placing labels on them, aparently because any damage to the "shiny side" can cause loss of data. I've certainly noted that even apparently minor scratches - that wouldn't do much damage to a "pressed" CD, will make a CD-R unreadable; and that the CD-R back surface is much more easily scratched.

John