The most important preventative measure in my experience: don't lay CDs upside-down in the name of “““protecting””” them! I know it's counter-intuitive, because I used to do it myself, but take a look at a cross-section of a CD and you'll see why it's the worst possible thing you can inadvertently do. The data layer is directly under the label, and the bottom of the disc is relatively well-protected in comparison: https://www.clir.org/wp-content/uploads/sites/6/fig2-3.jpg
This is also the reason why all-over-print CDs are better survivors than discs whose obverse design integrates the raw silver. Note that this is specific to CDs — DVDs and BDs have polycarbonate on both sides!
It took me years to learn this. Basically everyone forever has stored their CDs in the worst possible way, thinking they were storing them in the best possible way.
This is also the reason why all-over-print CDs are better survivors than discs whose obverse design integrates the raw silver. Note that this is specific to CDs — DVDs and BDs have polycarbonate on both sides!