Non-continuous reflective holograms or diffraction gratings are provided in various forms for authenticating documents and things, and for decorative and product packaging applications. In one specific authentication application, such a hologram or diffraction grating is firmly attached to a surface...http://www.google.de/patents/US5411296?utm_source=gb-gplus-sharePatent US5411296 - Non-continuous holograms, methods of making them and articles incorporating them
