The first banknotes in today’s sense were issued in Sweden during the 1660s. Since then, their imitation has been a major concern for issuers. Despite that, wide communications on notes, and particularly their security features, are a very recent phenomenon. Before the 1970s, communications were limited to big monetary reforms and keeping the restricted circle of law enforcement and correspondent banks informed on the security of new notes. As regards the public, secrecy surrounding banknote