I don't believe it's illegal to make a copy, even a perfect copy (see my comment below about the Nova episode paying an artist to repeat the process on camera o

I don't believe it's illegal to make a copy, even a perfect copy (see my comment below about the Nova episode paying an artist to repeat the process on camera of creating a duplicate). What's illegal is fraud in selling it as an original. The point of making it obviously a copy is to have a clear defense of "obviously I wasn't trying to make a perfect copy" should it later be sold as authentic--as happened to the 'forger' in the Nova episode. He genuinely sold it as a copy; it was only after several more sales (to which he had no connection) that it was fraudulently sold as authentic.