Well, counterfeiting is more than just getting a counterfeit printer. Getting the paper (technically fabric/clothe) right is often the harder part.

Btw, don’t know if others have noticed. Several years back the Secret Service made all scanner manufacturers put in a software check in their firmware so that if an user tries to scan US bank notes, the driver will abort the scan. I can fold the bill in half and scan correctly, but not the whole bill.