You can't photocopy this blogpost (abusing EURion in CSS)
css · 8 comments · 300 words · Viewed ~309 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 😉
Xerox VersaLink C7020, no problems whatsoever.
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