Counterfeit banknote recognition pen, counterfeit banknote detection pen is used to determine the authenticity of the bill. Its ink contains iodine.
General characteristics
The counterfeit recognition pen is most commonly used in the USA, Switzerland and the EU.
Typically, genuine banknotes are printed on cotton fiber paper and do not contain starch. When the bill is genuine, the mark left on it with a pen is yellowish or colorless.
Such pens are most effective against counterfeit banknotes printed on a standard printer or xerox paper. The chemical properties of American banknotes until 1960 are such that the pens for their recognition are ineffective.
Criticism
Critics of such pens suggest that their effectiveness is much lower than considered. Critics argue that professional counterfeiters use starch-free paper, which makes the pen unable to detect most counterfeit money in circulation. Skeptic James Randy has written many times about the inefficiency of fake pens. He shows their inefficiency in his lectures.
Randy claims to have contacted the US Secret Service inspector and asked if she works as advertised, to which the inspector replied that "she is not trustworthy." The Secret Service does not include such pens in its recommendations for detecting counterfeit US currency.
False Result
In addition, it was found that treating a fake banknote with a dilute vitamin C solution would lead to a false result.