I manage a small theater in Dallas, and we were recently told when depositing some money that there were 4 counterfit $100 bills in our deposit.
As such, we are now imploying these neat little pens that detect real/fake money. You mark the bill, and if the mark is yellow (well kindof a yellow/orange–it reminds me of the color of iodine), the bill is real, if the mark is black, the bill is fake.
now, I’m sure there is something in the paper of fake bills that causes the chemical to react and change color, but what is it? what is the chemical in the pen?
I don’t know what the chemicals are in the pen, but they change color based on the cotton content of the paper. U.S. currency is actually closer related to cloth than to paper. Standard paper is usually no more than 20% to 25% cotton content, currency paper contains much more.
Hey nugget, Have you found any bogus bills now that you have started using the pen?
It’s called Rag Bond paper, and is used when you want a document that can handle heavy use, or you want a special feel (“hand”) for your documents. It’s frequntly used in certificates, diplomas, invitations, and financial instruments. The US currency Rag Bond has a (literaly) top secret composition, and cannot legally be used for any other purpose in the US.
on an interesting side note, I’ve noticed that the pen also changes color (to black) if marked on a tri-flod paper towel or regular copier paper, however, it doesn’t change color on the ticket paper (our tickets are printed as needed using a thermal printer) on either side–that is, the thermal coating (only on one side of the paper) doesn’t seem to be what is inhibiting the chemical reaction.
what is the cotton content of thermal paper? (it’s the same kind that you get your recipt on at Wal-Mart, only cardstock)
I’m going to take several pieces of paper with me to work today and see which ones make the pen change color, I’ll report back later today.
none so far, if we do get one, I hope they let me keep it. (maybe with COUNTERFIT written across it)
Do they work? I am leaning on the NO answer; with a caveat:
I remember that James Randi recently tested those pens and even with newsprint the pens did not detect the fake, but the bigger flaw IMO is that counterfeiters already know about what paper reacts to those pens. People can get into a false sense of security by relying only on this test. I once saw one guy using the pen and he did not bother to check for other clues to find if the bill was good or not. Since time is added to the examination process, those pens discourage other more reliable methods of identification.
I think this system needs to be tested more. So, if you find a fake this way, let us know.
Perhaps they improved the formula recently and they are more effective than before. But if they were cheap pens, I doubt it.
If you do you will be breaking the law. In the US it is illegal to knowingly possess a counterfeit bill. We have some at the bank that we use for training purposes, but had to get permission from the Secret Service to keep them. I doubt you would be prosecuted, but why take the chance?
It looks like iodine because, coincidentally, it is iodine. The paper used for real money doesn’t have starch in it. Starch is present in most other paper, and the iodine reacts with the starch to produce the black mark (actually a deep blue/black).
As GIGOBuster pointed out, counterfeiters know this and avoid paper with starch. So, as Randi says, this actually produces a false sense of security. Randi once asked to a Secret Service agent, “Are these pens ineffective?” The agent answered non-comittally, “You could say that.”
Secret Service: how to detect counterfeit money. Notice: no mention of pens (or special lights, either).
I tested the paper, and here are the results:
Unused ticket stub:(termal side)the pen actualy does change on this one, i simply hadn’t noticed it before. it’s sort of a tan color with tiny grey streaks.
Unused ticket stub (back side)No color change.
Burger King reciept:(thermal side)Black.
Burger King reciept:(back side)No color change.
Single square of toilet paper:(Charmin)No color change, but when you view the mark where it bled through the baper it appears black.
Corner of newspaper:(Dallas Morning News)No color change.
Reciept from Ace:(regular ribbon-type printer paper)Black.
Those are pretty poor statistics for the pen.
Of course there is the security strip, the microprinting, and the watermark. There is also another way:
Rub a suspect bill on white paper. If it leaves a stain it is genuine currency. Counterfeit will not leave a stain. This works even with old currency, even though the rubbing may have to be done with considerable vigor, because the ink is special. I’ve heard it never quite dries completely.
That is so much simplier than examining a bill with a magnifying glass. But if it works, why doesn’t the U.S. Treasury Dept. mention it on their How to detect counterfeit site?
I tried the rubbing of currency on a piece of paper and sur’nuf it left a stain. So then I tried running an old piece of mail I had laying around and it left a stain. If any thing the piece of mail left a bigger stain. Then in the interest of completeness I went and got some old paper work that was dated a year and a half ago and tried it. The biggest stain yet. Admittedly I don’t have some counterfeit bills laying about to further check this theory with but it doesn’t look good so far.
Hmmm. I learned the stain theory along the US-Mexico border, where all the merchants seemed to have faith in it. Could be bogus. Sorry 'bout that!
A good way to check for counterfeits is to use a blacklight. We have a device with a blacklight that will cause most counterfeits to fluoresce (glow), will cause only the security thread to glow in color on real currency, and there is a backlight that lets you look closer at the other features (like the watermark). Colors that the security threads glow are: $100.00 = red; $50.00 = yellow; $20.00 = green; $10.00 = orange; $5.00 = blue.
I have doubt in the blacklights, actually.
One of the bars I frequent has blacklights all over, and roughly one out of ten bills glow. I doubt that counterfeit money is really that common. Additionally, most of the glowing bills I notice are ones, since they are left lying on the bar as tips, and I sincerely doubt that anyone making counterfeit money is bothering with one dollar bills. Lastly, the bartenders freely accept the glowing bills and deposit them in the till, meaning the bank gets 30-40 glowing bills PER DAY from this bar - and the bank has never complained. I think this method of detection is unreliable, to say the least.
mischievous
Perhaps I sould clarify the above post. What I meant was that the entire bar was lit with blacklights, so any bill that is lying on the bar is exposed to them. Everyone at the bar can see if the bills glow or not.
mischievous
Last I checked, you didn’t need any special equipment at all to check the watermark or security strip, and those would be a lot harder to counterfeit than the starch content or fluorescence. Don’t make things hard on yourself.