A transfer foil for use in a safety document includes a multilayer structure having a carrier layer and a plastic layer in which diffraction structures, for example holographic structures, are embossed in the form of a relief structure and which is combined with a reflective layer. The plastic layer...http://www.google.de/patents/US6294241?utm_source=gb-gplus-sharePatent US6294241 - Security document and method of producing it
