Modern copiers can tell when there's money on the glass
I had an odd experience recently. I mistakenly took a friend's jacket after a party. He jokingly said that he had $500 in his pocket, and that it had better be there when he got it back. I thought for a joke that I would copy a $50 bill and doctor it up to look like $500.
In my first attempt to copy I got about half an inch and then it stopped. I put a color ad in the printer and it worked fine. I tried once more with the fifty and got the same results as the first time. Do manufacturers put a chip inside to prevent counterfeiters?
— Roland, Medford
It appears you've stumbled across one of the weapons in the fight against counterfeiters during your jacket prank.
Modern digital copiers and imaging software such as Adobe Photoshop and Paint Shop Pro are equipped with a Counterfeit Deterrence System that can detect US dollars and many other world currencies. The technology is developed in cooperation with the Central Bank Counterfeit Deterrence Group, a group of 32 central banks and note printing authorities, according to its website.
How do they do that? The process is simple... just kidding, it's actually rather technical. In simplest terms a machine can detect currency based on certain patterns printed on it. For example, a particular pattern of yellow, orange or green circles is hidden in most currently issued US bills greater than $5, as well as the Euro, Japanese yen, British pound sterling and Indian rupee to name a few. Those circles are often called "Omron rings" named after the Japanese imaging company that's believed to have developed the technology seen on bank notes around the world beginning about 1996.
The rings are visible on the back of the $20 and the $5 bill we had handy (a $50 bill being somewhat out of some journalists' reach in time for deadline). The seemingly random assortment of yellow 20s and 05s tip off computers that someone could be up to no good with the machine — even if it's just a prank — and stops the process.