speaking of extraordinary efforts, there was a case the secret service handled. a guy walks in a bar and orders a drink. to pay for it, he drops a $100 bill on the bar. the waitress goes to pick it up but notices the green ink is running off the "bill" onto the bar. she called the cops and the guy was arrested. turns out the guy used a green pen and painstaking recreated the bill.
There’s a fellow named J.S. Boggs, you could probably find a webpage on him. He *freehands* US notes, and very well. As you might imagine, the secret service has taken a somewhat dim view of this gentleman. Apparently he doesn’t try to pass them off as genuine currency, but upfront will offer them in “trade”, say, at a diner or restaurant.