An optically readable media (10) has an information-encoding layer (16) and at least one color-forming layer (12) that embodies an optical readout-limiting mechanism. In a first embodiment the at least one color-forming layer contains an additive that does not interfere with the optical readability of...http://www.google.fr/patents/US6982109?utm_source=gb-gplus-shareBrevet US6982109 - Method for rendering surface layer of limited play disk lightfast
Method for rendering surface layer of limited play disk lightfast
