[ralferoo]

Even 1000dpi might not cut it. Remember the stories about really old texts on parchment that they discovered had been re-written on reused parchment? At certain specific wavelengths they could "see" the original text. If you just have a plain old RGB scan, that's no longer there.

More for paintings, and less so for books (except very old handwritten ones), is that the ink or paint used has its own characteristics. It might look very different from different angles due to the light reflecting off the pigment in different ways. Doesn't matter how high a resolution scan you have, it's going to be hard to scan that, and even harder to display it on a screen.