One aspect of the present invention is a method for marking metal or other product for its identification. This method includes the steps of: (a) forming on said product or on a tag to be attached to said product a layer of coating containing an additive that is darkenable under the action of a CO.sub.2...http://www.google.fr/patents/US5855969?utm_source=gb-gplus-shareBrevet US5855969 - CO.sub.2 laser marking of coated surfaces for product identification
CO.sub.2 laser marking of coated surfaces for product identification
