These pens comprise an iodine-based answer that reacts with the starch current in typical wood-based paper. Genuine foreign money paper is mostly made with out starch, so the answer stays pale yellow or clear. Counterfeit payments typically make the most of customary paper, inflicting the pen’s mark to show a darkish brown or black, indicating a possible forgery.
This straightforward, low-cost technique offers a fast preliminary screening for suspect banknotes. Whereas not foolproof, it affords a helpful first line of protection for companies and people dealing with money transactions. Traditionally, counterfeit detection strategies have been extra advanced and fewer accessible. The event of those pens democratized the method, placing a fast verification instrument within the palms of the general public. This accessibility considerably contributes to deterring the circulation of fraudulent foreign money.