You can't photocopy this blogpost (abusing EURion in CSS)
By @edent
· css · 8 comments · 300 words · read ~290 times.
Do you know about the EURion constellation? It is a pattern which is embedded into some modern banknotes and has a curious property. Most modern photocopiers will, if they detect the pattern, refuse to make a copy.
Try it for yourself - stick a €20 note into your nearest Xerox machine and try to print out some illicit currency - see what happens!
It goes a little further Some printers will refuse to print anything which contains this pattern. Lots of image editing software will throw up dire warnings if you try to open a file with it embedded.
Now, I know what you're thinking. Usually web browsers won't print background images. Even if you mark them as !important. And don't try using @media print because that won't work either.
Instead, you need to use print-color-adjust: exact; to tell the browser that you want to print exactly what is seen on screen.
If you can print this blog post in colour - and then photocopy it - do please let me know 😉
@Edent HP M477fdw printed it and then photocopied it without complaint. Now granted this is a desktop MFD rather than an office photocopier but still…
@Edent [makes note to get that face tat before going on the lam.]
@Edent
So every enterprising kid is now forced to locate an image of a banknote without that pattern, in order to exercise his freedom of the press rights? That is unacceptable gov interference! Why should the central banks be the only ones who can print money at will? That measure will put the European economy behind those of China, Russia, North Korea...
My Epson EcoTank Pro ET-16600 MFP printed and photocopied it just fine. Perhaps only patterns the size they'd appear in an actual bank note are blocked.
@Edent I had a photograph that included US Dollar bills that I tried to open in Photoshop a few years ago so I could crop it for a website. Photoshop refused to open the file.
Was able to paste the screenshot into Photoshop Elements and it didn't throw up any warnings -- and I know Photoshop Elements checks for that, as I got the actual warning earlier this week when I edited some photos I had taken of the new King Charles III banknotes.
Xerox VersaLink C7020, no problems whatsoever.
Printed just fine in the USA on a Canadian manufactured Brother MFC-L3770CDW series and then scanned back in on the same machine.
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