30, 20, and 10 Years Ago in OPN

“Thin Film Security Devices (TFSDs) … can be observed … without the use of special viewing devices. Their effect cannot be reproduced by printing or xerography and they cannot be stripped from one document and transferred to another …TFSDs have been recently introduced into the marketplace and applied to British Columbia drivers’ licenses …There is considerable interest in this development in other countries and use on other devices, including banknotes, is expected in the future.”