More reports-How many corrupted CD-R's with time?

That's why most mid to large companies back up their data to tape. As it turns out, CD-R is not a very reliable or long lasting data archival medium, whether that data be music or source code. SO maybe those DAT machines weren't such a bad idea after all...

I've had about 200 CDs from the 80s corrode, some very seriously. They were all pressed by PDO (Philips Dupont Optical) in Blackburn, Lancashire UK. ALL were classical titles and most, fortunately were replaced free of charge by PDO. The major labels with the problem were Hyperion, ASV, Unicorn and DG Archiv. A corrosive chemical was introduced into the manufacturing process that attacked the aluminum layer in the CDs.

Ketchup: What makes you say that labels on CD-R's will compromise lifespan? Or soft sleeves? What could merely touching the polycarbonate do to deteriorate the burned layer inside? BTW, as I recall Mitsui promises >100yrs. for their Gold disks.

Zaiksman,
Your comments have made me realize that I was not completely clear in my earlier post. I don't believe that the sleeve itself that can damage the cd but the dust and dirt that gets in the sleeve. Dust and dirt also gets in jewel cases but because the cd never touches the case there isn't a possibility of scuffing the cd.

As for the stick on labels that can be put on cds, I have only heard of other accounts of labels "lifting" or crinkling over time and pulling the reflective layer off of the top of the cd. This is arguably the most important layer to protect. The bottom of the cd can take light scratches, but if the reflective surface gets scratched or damaged (like from old, dried out wrinkly labels) the cd is pretty much done. As I said earlier, I have never seen this first hand but that's because I have never put a stick on label onto one of my cds! I was also turned off by labels because I thought they could very easily imbalance the disc if not put on perfectly centered which is very possible.

Ketchup: The only reflective layer in a CD or CD-R is sandwiched between the two layers of clear polycarbonate which protect it. I have peeled just-applied labels back off disks, and it doesn't damage anything except the label. Scratches to the polycarbonate itself can be polished out if need be, but I get your point about dirty jewel boxes being better than dirty sleeves, if dirty at all one must be (a label should actually be protective from scatches, but since that's not on the data side of the disk it doesn't matter either way). I've never had a label on a disk get "wrinkled" over time, but very occasionally one will be discovered to have developed an air bubble or two underneath, which so far have always smoothed-out easily and not recurred. As for imbalance, I doubt this is really a problem; I've certainly never noticed a change in sound after labelling a disk, while the die-cut labels ought to be no more irregular than the disks themselves, only much lower in mass, and using the label-applicator jig provided with any labelling kit ensures perfectly concentric placement. I can't imagine how you get along just writing something tiny at the center hub -- I'd go nuts not being able to identify my disks at a glance while on the road! But I have to admit, making an aesthetically appealing label can sometimes be more time-consuming than making the recording itself...