Canadian dollar banknotes from the 2011 “Frontiers” series
There is an old saying that central banks should be at least one step ahead of counterfeiters. A banknote is just a piece of paper and its value depends on trust in the issuer, an important part of which is the security of the banknote. However, the first counterfeit notes were discovered shortly after the first banknotes were issued. Since then, the result has been an endless race between the issuing authority and the perpetrator.
In the early days, as the first measure, using watermark paper,