We sometimes think of paintings as like autographs. It’s only Mick Jagger’s autograph if he signed it, with his very hand. And it’s only a Vermeer, say, or a Rothko, if Vermeer or Rothko themselves actually made the pictures.

This makes good sense when it comes to autographs. A signature is a person’s mark. By affixing our mark, we sign the deal; we make the commitment; we write the check. An autograph matters because it certifies.

But none of this is true of paintings. (read on)