Guardian substrate is a coated polymer film that has demonstrated its suitability as a substrate for variety of printed security documents. Guardian consists of a transparent flexible polymer core layer that is coated on both sides with an opacifying coating that can be printed on using conventional printing techniques. Probably the most evolutionary feature of this substrate architecture is that is provides the facility to create areas on a document that are either transparent or semi-transparent, depending on how the coating is applied. Now for the first time documents can be secured using devices that rely on transmission through a medium with high optical clarity. Guardian substrate provides the flexibility of varying the degree of opacity to suit the device being employed. This paper discusses the benefits of this important capability, using a number of new and adapted devices to demonstrate the potential of this new platform.

Date Published: 7 April 2000
PDF: 12 pages
Proc. SPIE 3973, Optical Security and Counterfeit Deterrence Techniques III, (7 April 2000); doi: 10.1117/12.382185

Published in SPIE Proceedings Vol. 3973:
Optical Security and Counterfeit Deterrence Techniques III
Rudolf L. van Renesse; Willem A. Vliegenthart, Editor(s)