Xerox Develops New Way to Print Invisible Ink

scott3778 writes "Xerox said on Wednesday that its scientists have perfected a new method for printing hidden fluorescent wording using standard digital printing equipment. According to the company, the discovery paves the way for customers and businesses alike to add an additional layer of security to commonly printed materials such as checks, tickets, coupons, and other high-value documents. The hidden fluorescent words and letters show up only under ultraviolet light, said Reiner Eschbach, a research fellow in the Xerox Innovation Group, and the co-inventor of the patented process. What's more, the method for printing them doesn't require the use of special fluorescent inks."

Comments

Maybe not as far as it sounds

[PCM2]

According to the article, what they're doing is exploiting the fact that most paper has been washed with fluorescent agents to enhance its whiteness, and so will tend to fluoresce somewhat anyway. (It's the same way they make "color safe bleach": It's not bleach. It's fluorescent dye.)

What they may be doing is using the matte properties of printer toner to dull the fluorescent sheen of most of the paper by applying a difficult-to-detect stochastic pattern over the ostensibly white areas of the printout. The areas that are still completely white will seem to fluoresce compared to the areas that have been colored "eggshell white" by the printer. But that's just a guess.

even worse

[frovingslosh]

From the article:

Xerox expects that over time, the technology will be used in personalized checks that will have the account holder's signature printed in a fluorescent stripe.

So they want to print my signature, right on the check, in a form that anyone with a UV light can read (even suggesting it is so the mrechant can verify "my" signature that way). How idiotic! First of all, the last thing that I want is my signature printed on the check so that any thief who gets hold of the checkbook can have a sample of what to practice signing my name like (it would be far better to use computer technology to show authorized bank tellers my segnature seperate from the check, easy enough to do with current computer technology). And worse, in an age where anyone can order checks with any account number on them (or even print them themselves), I hardly want the identity theives to be able to print their version of "my signature" on the checks they print so that they can convince someone accepting the check that it's valid because the signature matches.

Re:even worse

[Kijori]

And worse, in an age where anyone can order checks with any account number on them (or even print them themselves) You've always been able to do this - you can take a piece of paper right now, write your bank information and payment instructions on it, sign and it can be used as a cheque. There was even a case in Britain of a payment order painted on the side of a cow being held to be a valid cheque. Now, I agree with the fact that printing someone's signature on the cheque is an awful idea, but being able to have cheques on any account number is nothing new.

Nice and all, but it seems to depend on the paper

[Ogi_UnixNut]

I know its not being a proper member of Slashdot if you RTFA, but the idea of a method of printing invisible markings without ink was quite something. Only when reading TFA did I come across this little gem:

He and the group realized that most paper manufacturers already inject fluorescent brightening agents in paper to enchance its "whiteness," so they worked to create certain combinations of toner that would allow the paper's fluorescence to shine through when exposed to ultraviolet light, Eschbach said.

Very very clever, but it relies on the presence of fluorescent brightening agents in the paper (these are those "ultra bright/white" paper brands that they charge a premium for). This means that those of you of a tin-foilish predisposition can make use of paper which does not contain these agents in order to prevent your printer making any invisible markings using this technique. Unfortunately this makes counterfeiting not that much easier, as the process that banknotes use to add invisible markings are different to this.

It also means that most company paper will not work (I don't know about other people, but where I worked, the paper was usually the cheapest economy stuff you could find, primarily because they used so much of it).

I can assume that either the premium paper companies are in for a surge in sales from this or all the other brands of paper will start adding these agents and it will become standard. We shall see.

P.S I think the article meant "enhance", not "enchance".

Re:Nice and all, but it seems to depend on the pap

[solitas]

As I read it, they're working with the difference in contrast between the ink and the paper background. You throw a UV light on a paper that's fluorescing blue with shiny yellow dots on it that are primarily reflecting the same color (and adding a little bit of their own fluorescence) and the two components have approximately the same luminosity, and they'll look pretty much invisible - the eye can only do just so much detecting colors in this situation. And the overwhelming blue from the paper will effectively hide the dots.

BUT, if you have a long-pass filter in front of your camera (use a filter with a cutoff somewhere between the blue of the paper and the yellow of the dots - you can buy pretty sharp filters from Edmund - and a greyscale camera) then those dots will show up decently against the apparent 'darkness' of the paper.

(I do a bit of UV photography at work using tracer powders and indicators on plastic, metal, paper, and skin, and filters with monochrome cameras work great.)