MOTM

I consider CDRs to be the most reliable medium for long term 
storage.  I have had a number of hard drive crashes and I have seen 
badly shedding tape.  I have even seen vinyl LPs (Yes, I'm that old) 
with mold growing on the surface.  I have never had a CDR or CD 
failure.  I may eventually develop the same level of trust for DVDs 
and DVDRs but not just yet.

As many of you probably know I run a commercial recording studio 
based around ProTools.  After every session I backup every new track 
and the master files to CDR and insist that my client take it home 
and keep it.  (I do charge them for this service.)  I also copy 
everything to a second, slower harddrive I keep for the purpose of 
running backups.  So the data exists in three places.  After clients 
have finished their projects I make a CDR copy of everything for 
safekeeping in the studio, in addition to the CDR copy the client 
should be keeping.  After verifying that the data on the CDR is 
intact I then erase my ProTools hard drive and my running backup 
harddrive.  So all active projects exist in three places and all non-
active projects in two places.  I keep the CDRs stored in jewel 
boxes in a climate controlled storage area of the studio which is 
usually dark and has no windows.  I have several thousand.

I have seen too many drive failures to keep everything archived on 
hard drives.  If you drop a CDR it is likely to still be readable.  
CDRs are immune to magnetic fields.  It may be possible to damage 
them with UV but if you keep them out of the sun and bright lights 
there should be no problem.

I use a combination of cheap spindle mounted blanks (but major name 
branded) and expensive gold discs (usually Apogee or Quantegy)