interesting yahoo article on counterfeit money made in Peru: link: http://news.yahoo.com/peru-global-leader-dollar-counterfeiting-072833886.html
Just happened to read that before coming here. It appears that they have overtaken Colombia as the leading counterfeiter of US currency. They net about $20K for every $100K counterfeited. What I didn't understand is why they choose to distribute the counterfeit $100 notes in the US and the $10 & $20 notes in nearby South American countries. It would seem to me that the smaller notes wouldn't undergo closer scrutiny in the US as would the C-notes. Chris
"Peruvian counterfeiters' handiwork will always get tripped up by the infrared scanner banks used to authenticate currency" Shouldn't that be "ultraviolet"? What's an infrared scanner going to show?
See here for example: http://www.new-euro-banknotes.eu/Euro-banknotes/Security-features/ADDITIONAL-FEATURES/THE-NEW-5 Now this is a €5 note, but you can click on "Infrared Properties" and see the effect. Then click the small "Back" link to get back to the other features, such as UV. Christian
Holy cow, that's amazing! Two separate bands of UV-fluorescence with separate details, plus IR-reflectivity details? That's really cool, but UV-C emitters (and the attendant safety equipment) don't come cheap, at least compared to near-UV LEDs. And you're going to need something like a video camera/display to pick up the IR detail -- an IR light alone won't do the trick.
On U.S. currency, the IR features are on the back side. The green intaglio printing is actually done with two different green inks, one IR-dark and one IR-bright, which look identical in visible light. There's a vertical stripe about half an inch wide printed in the IR-bright ink, and the stripe is located in a different position on each denomination. Makes it easy for IR scanners to identify denominations (some vending machine currency readers make use of this feature, as do some of the currency readers used by the blind). This is a relatively new feature; I think it was introduced in 1999 or so. Not all of the 1996-generation "big head" bills have it, but all of the 2004-generation "Kodachrome" bills do.
