Interesting, it used to be a set of dot patterns that marked bills to prevent copying bills. But apparently there is even more stuff in them.
http://sploid.gizmodo.com/heres-the-reason-why-you-cant-photocopy-money-1782060136
Interesting, it used to be a set of dot patterns that marked bills to prevent copying bills. But apparently there is even more stuff in them.
http://sploid.gizmodo.com/heres-the-reason-why-you-cant-photocopy-money-1782060136