CompuServe Messages

Excuse me for barging in, but I can answer that and John can confirm or deny and add his own eight bits – rest assured that he will. CDs are made by molding polycarbonate with metal stampers. They are then metallized with an extremely thin layer of aluminum (write-once discs are metallized with gold). This reflective layer is very important because it is what reflects the laser light – the pits and lands molded into the disc bounce the light back at different intensities, which are detected and converted to digital data. On top of this metallic layer is a coating of lacquer which seals the disc and hopefully protects the metal from oxidation. The label is printed on this lacquer surface. A scratch on the label side of the disc can much more damaging than one on the "read" surface, because it is more likely to damage the pits and lands. A scratch on the data side of the disc can usually be compensated for by EDC and ECC. Right, John? Dana Parker