Due to the unexpected development of high quality photocopier machines, a strong interest towards development of anti-photocopying technology has arisen. High quality photocopiers make it unduly easy for someone to make unauthorized copies out of confidential documents, thus effective countermeasures have become necessary. However, though many attempts have been made to accomplish such countermeasures, the effective protection against these acts is still insufficient.
As a result, the number of patents related to this field has recently increased dramatically.
This paper is a summary of the patents and describes the technological trends on the anti-photocopying paper.
