[SGVLUG] CD permanency

[Marsden MacRae]

On 10/14/05 Dustin said

> Something else I forgot to stress: optical discs aren't really permanent.
> They work just fine for an ongoing backup process of data that you keep
> "live" on a hard disk somewhere, but I would be unhappy if someone took
> what I said as a licence to archive their family photos to a CD/DVD and
> then delete them, figuring the disc will be there forever.
> 
> Dustin 


I can't find (digging through my trash, er "archived LUG threads") any 
further discussion on this.

Can anybody expand on this? We're about to buy more disks, is there some 
criteria I should use to determine "which disk to buy" for "permanence"? 
Off list or pointers to informative sites welcomed!

thanks for your help
Marsden