Since most of the keys to lifetime lie in the purity of the materials used in the disc manufacturing, it is difficult to tell the quality of a disc just by looking at it. There are some clues to look for, however. Using an overhead projector or bright sunlight, look at the metal layer from the read side of the disc (the side without the label). A high quality disc should be essentially opaque in the data area. Large numbers of pinholes (they will look like bright stars) or a semi-transparent metal layer should raise some concerns. If you can read the label completely, the metal layer will probably not stand up in the long term. You should also look at the label/sealcoat side. This surface should be smooth and free of defects. Any dimples or holes in the seal coat would allow outside agents to attack the metal and shorten the lifetime of the disc. The sealcoat should also extend past the metal surface on both the inside and outside edge of the disc, to perfectly seal the surface.

Copyright 1996 Imation. All rights reserved.