[Ken H]

That sounds like BS. Artists sketch works of art in museums all the time. I’m sure many of these works are on loan from private collectors. Never heard of a copyright issue.

[Thorliveshere]

That sounds like BS. Artists sketch works of art in museums all the time. I’m sure many of these works are on loan from private collectors. Never heard of a copyright issue.

Yes, you can sketch the works of other artists, but when you try to sell them, that's an entirely different issue. Of course, when enough time has passed, some artwork becomes public domain, but then there's the problem of artistic integrity. If you painted your own Mona Lisa, then you're just a hack or a forger.