Kinda silly if you ask me. Hey, I heard a rumor once, that the pen test will NOT work on currency if it is too old, and I thought that the 1976 $2s were too old, so, when that pen test went positive for no counterfeits, I breathed a sigh of relief. Would my $500 note pass the pen test if its real (I foolishly bought my $500 bill off eBay, so unfortunately, I'm not sure if its real or not), or is it too old?
Your $500 bill would flunk the pen test for sure regardless if it is authentic or not. They were last printed in 1945 and the pen test doesn't work on currency printed before 1959 or there abouts as the paper is different. Unfortunately, many cashiers lack the ability to take 3 seconds out of their time to read the message on those pens or pen packaging that state this. It is not uncommon for cashiers to falsly assume that that 1950 $10 bill that someone tried to spend is fake and through their ignorance have caused countless problems for customers over the years for being dependent on the pen which the government doesn't even suggest be used! lol
Your going to pen test a $500 note? Good way to make an XF a VF or worse? A loupe is all you need! Most counterfeits are garbage up close. Forgeries on the other hand you have to look very close at the intaglio, and cross hatching. Not unheard of for a forger to just change the signatures or change series letters or dates or even serial numbers for that matter. We have allready seen Doctors turn Goods into XFines!!!
Don't blame the clerks! The (stupid) employer insists upon the use of the pen. The (stupid) employer also insists that the clerks never use their own good judgement. The clerks, being afraid of the employer (remember the golden rule: He who has the gold, rules!) never use good judgement, they use the (stupid) judgement imposed upon them by the employer.