These pens comprise an iodine-based resolution 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 usually make the most of normal paper, inflicting the pen’s mark to show a darkish brown or black, indicating a possible forgery.
This straightforward, low-cost technique offers a speedy preliminary screening for suspect banknotes. Whereas not foolproof, it gives a useful first line of protection for companies and people dealing with money transactions. Traditionally, counterfeit detection strategies had been extra complicated and fewer accessible. The event of those pens democratized the method, placing a fast verification device within the palms of the general public. This accessibility considerably contributes to deterring the circulation of fraudulent foreign money.