This is a key point. Detection by human is fairly limited as they only use their own, easily fooled, eyes and a detection pen, which can be fooled if starch-fre

This is a key point. Detection by human is fairly limited as they only use their own, easily fooled, eyes and a detection pen, which can be fooled if starch-free paper was used by the counterfeiter [1] [1] https://en.wikipedia.org/wiki/Counterfeit_banknote_detection_pen https://en.wikipedia.org/wiki/Counterfeit_banknote_detection...