A light diffracting structure 10 in an authenticating pattern 20 especially for an authentication label 30 is used for authenticating and protecting against forgery various valuable objects. The light diffracting structure 10 has unique parameters generating a uniquely colored pattern. The unique parameters...http://www.google.es/patents/US5629070?utm_source=gb-gplus-sharePatente US5629070 - Authentication label and authenticating pattern incorporating diffracting structure and method of fabricating them
Authentication label and authenticating pattern incorporating diffracting ...
