Maybe this deserves (or has even had) a separate thread, but apropos of counterfeits, I’ve heard that a huge number of paintings in art museums around the world are thought to be counterfeit. I know, I know, how would anyone know? And I also know that if you can’t tell the difference then maybe the difference isn’t significant. However - do fakes count for more than 20% of holdings in museums?
I read about 10 years ago it was thought North Korea was putting out a good amount of fake bills - or trying to put them out. Maybe they still are.