Painting is a perishable art. From antiquity have survived statues, tombs, mosaics, some murals here and there, artifacts of all kinds, and the sublime monuments of architecture; but of the great Greek and Roman painters, we have no original works.
We don't even know what the ancient painters looked like, their portraits are imagined by the Renaissance masters. I'm still putting Polignot's portrait here because it should be more interesting than the fictional characters of some stupid video games.
https://en.wikipedia.org/wiki/Polygnotus