-all western art before about 1400 kinda sucked, then we learned how to draw people -all western art after about 1915 absolutely sucks, since we forgot how to draw people (and everything else) -everything in between those years is so impressive it's almost baffling -best way to learn about art history is first to read a giant art history textbook and look at the pictures and learn words like baroque etc. take advantage of this; it's rarely true. -also the best way is to go to museums but that's kinda pricey -private collectors(/popes) who happened to really enjoy a given artist a) shaped our perceptions of who could paint and who couldn't more than anything else and b) saved a ton of art which is now priceless and would otherwise be forgotten or never have gotten famous -- like you say, canvas weren't cheap. artists painted over their old art. space wasn't cheap either, so they threw stuff away.