Per this story
I’m guessing that all copiers and scanners built since 1998 are required to have some sort of recognition software built in to make it impossible to copy the new bills.
Google “eurion constellation”. This is a repeated pattern of five dots in a specific arrangement that appears on many new banknotes.
Partway down in this thread are some images of the new Canadian twenty-dollar bill. The pattern isin the horizontal yellow area at the lower centre of the front of the banknote, and also at the lower centre of the rear.
Apparently many newer copiers and the newest version of Photoshop will refuse to copy images with this pattern. I don’t know of any specific dates that this was implemented… apparently it’s only the newest version of Photoshop that halts; my scanner and Photoshop 5.5 had no problem scanning a hundred-dollar bill, for instance, which definitely has the pattern. We just got new copiers at work; I’m going to try a twenty on them.
Um, I just copied it to my desktop and sent it to my printer just fine.
It doesn’t look all that great, but who expected it to?
Such software (or firmware) protections are trivially easy to defeat, and are never going to thwart a determined crook.
Most Colour laser copiers, for example, don’t even require any sophisticated tampering to circumvent the protection. (Don’t bother asking.)
Of course, with the proliferation of affordable colour reprographic equipment, even a safeguard that only thwarts the casual idiot who has the bright idea of passing an inkjet $50 in a dark tavern is going to prevent a significant amount of criminal activity.