In order to form safety markings at a planar card made of a plastics material, which card may be used, for instance, as credit card, this card is built up from at least two parts. The inner border area between these two parts comprises a relief-like structure which is the carrier of the safety marking....http://www.google.es/patents/US4564409?utm_source=gb-gplus-sharePatente US4564409 - Planar card made of a thermoplastic material having visually recognizable safety markings and method of manufacturing such card
Planar card made of a thermoplastic material having visually recognizable ...
