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Yellow Dotted Printer Paper

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Almost all colour laser printers add a repeating pattern of very small yellow dots to printed page. This pattern, which is barely visible except under blue light and magnification, encodes the make, model and serial number of the printer and, in some cases, the date and time of printing. Its purpose is purportedly to enable the tracing of forged documents.

MaxCo., true to its company motto of "Never Knowingly Responsible", is therefore proud to announce its range of pre-dotted printer paper. Each sheet is bespeckled with superimposed and randomly-offset yellow dot patterns copied from a wide range of colour laser printers, foiling any attempts to trace the source of anything printed thereupon.

Moreovermore besides, we are also about to launch our range of "Copy-Me-Not" paper, preprinted with the little constellation of five somewhat larger yellow dots which appear on banknotes, and which colour photocopiers stubbornly refuse to copy. Any document printed thereupon will, when photocopied by a modern copier, produce only a black page.

MaxwellBuchanan, Jul 28 2013

EURion constellation http://en.wikipedia...URion_constellation
The anti-copying mechanism referenced above [ytk, Jul 29 2013]

Yellow tracking dots by laser printers http://seeingyellow.com/
[MaxwellBuchanan, Jul 29 2013]

The Garden of Cyrus, or The Quincunciall Lozenge, or Network Plantations of the Ancients, naturally, artificially, mystically considered http://books.google..._ge_summary_r&cad=0
Thomas Browne, 1658 [pocmloc, Jul 29 2013]


       Bun for the first part, but unfortunately the EURion constellation, as the anti-copying pattern is known, is generally only respected by color copiers. The vast majority of copiers, even modern ones, would be unaffected.
ytk, Jul 28 2013

       I didn't know this. Does it work with black light?
Ling, Jul 29 2013

       Can you arrange it so when it hits a predefined prime number of prints function X goes into effect?   

       Function X is where one page of the document gets printed with coffee cup rings, lots of crossing out and apparently handwritten annotations in the margin saying what utter tosh the author has written.
not_morrison_rm, Jul 29 2013

       //Does this prevent scan and print as well as copy ?//   

       I'm not sure about scanning, but many image editing programs (like Photoshop) will refuse to operate on images containing the EURion constellation (or other anti-counterfeiting watermarks). (link for more info)
ytk, Jul 29 2013

       // the anti-copying pattern... is generally only respected by color copiers// Yes, that's true.   

       //Does this prevent scan and print as well as copy ?// Not sure; I would guess that high-end scanner/copiers apply this to the scan as well as the print parts.   

       //Does it work with black light?// If you mean the banknote protection - no, because it's designed to work with normal copiers that don't have a blacklight. For the yellow-dot-encryption of regular colour laser printouts, the dots are printed using the normal yellow toner of the printer; they might be easier to see under blacklight, but they can be seen by eye using a blue light and a magnifying glass; you can also see them if you take a high-res digital photo and play with the "yellow" channel on the image. But the naked eye isn't very good at seeing yellow on white.   

       //some other stenographic system// Yes, there are some anticopying features in addition to the Eurion pattern. I tried playing with banknotes (UK mainly) and found that whilst the Eurion cluster is enough to prevent colour-copying, there are also some other non-obvious parts of the image that prevent copying.   

       But mainly this idea is about thwarting the yellow microdots that encode all of your colour laser prints.
MaxwellBuchanan, Jul 29 2013

       //Photoshop and other image programs rely on some other stenographic system// You mean they have one of those courtroom typists?
MaxwellBuchanan, Jul 29 2013

              //Does this prevent scan and print as well as copy ?//      

       Medical prescription paper does. I grabbed a sheet from our veterinary pad and tried it out on our HP scanner/copier and my mother's Canon does-it-all machine. VOID.
Alterother, Jul 29 2013

       Interesting. Does it have the Eurion code on it? Or something else? Presumably you could scan it in monochrome through three different colour filters, then combine the three images...
MaxwellBuchanan, Jul 29 2013

       I dunno from no Eurion code, but whether scanned-and- printed or simply copied, they always come out with the word VOID blocked across them and a two-part serial number along the part where the doctor signs.
Alterother, Jul 29 2013

       I haven't tried the monochrome idea, but it still voids if you scan it in color and print it in b&w.
Alterother, Jul 29 2013

       It's not a specific code, actually. It's a special type of printing. One common technique involves printing the word “VOID” so it is easily visible to both the naked eye and the copy machine, but the surrounding background is effectively invisible to the copier (or beneath the threshold for visibility when converted to monochrome). Since the word gets reproduced by the copier but the background doesn't, it stands out. Another method involves taking advantage of the reduced resolution of the copier, so that a series of apparently unconnected dots and lines blur together a bit and form a word when photocopied. It's not just prescriptions, either; checks are commonly printed using this kind of security method.
ytk, Jul 29 2013

       Ah, OK - that's different from the Eurion system, which relies on firmware in the scanner/copier. If you try to photocopy a banknote in colour, most copiers will just print a completely black (not blank) page, even beyond the bounds of the note.
MaxwellBuchanan, Jul 29 2013

       [Max] - next time you visit your competitor's MSL*, take something you can copy. Take a yellow-inked rubber EURion stamp, stamp your original just before you put it on the glass, and it'll probably fail to copy. But (and here's the bonus) the fresh-stamped ink will transfer to the glass; it's pretty transparent so it'll be very hard to see, but will prevent the copier from working on anything until it's cleaned off.   

       (or just stamp the glass...)   

       *Mad Scientist Laboratory
lurch, Jul 29 2013

MaxwellBuchanan, Jul 29 2013

       I'm so disappointed, my computer and scanner and printer had no problems with me making a duplicate of a banknote covered in those little dots. (OK I worked out I bought the scanner in 1995).   

       Do you think the dots are patented, If I insert a few discretely into my letterhead will I get sued? I just like the idea of my correspondents having mysterious problems when they try to photocopy my letters to them.
pocmloc, Jul 29 2013

       [poc], can I borrow your printer and about 250 toner cartridges?
MaxwellBuchanan, Jul 29 2013

       You can bloody well buy your own toner you blagger. Also my printer does make yellow dots.   

       I have not yet tried printing the quincunx pattern from Wikipedia, that is the next experiment. Anyone else have any success printing a yellow eurion shape?
pocmloc, Jul 29 2013

       I tried to duplicate the Eurion, based on images from the Interweb, and found that it still printed and scanned on a protected colour copier. There is some feature of it that is not easy to replicate. There was (but apparently no longer is) a utility available to Eurionize PDF documents.
MaxwellBuchanan, Jul 29 2013

       Pretty much all modern laser printers do.
MaxwellBuchanan, Jul 29 2013

       Hmm, so the Euro could be replaced with small paper yellow circles...
not_morrison_rm, Jul 29 2013

       Sadly not. The yellow circles are part of the system that allows scanners/copiers to recognise potential banknotes and refuse to scan them. Sadly they are underadequate to cause a banknote scanner to accept a piece of paper as being a banknote. This is probably why yellow toner cartridges are not significantly more expensive than the other colours.
MaxwellBuchanan, Jul 29 2013

       That's shocking, I mean ,if they aren't prepared to take a chap's word on the value of those yellow circles, what is the world coming to?
not_morrison_rm, Jul 29 2013


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