art websites

Monoskop

monoskop.org

Works without javascript. Independent art wiki, a lot of downloadable material.

The Art Story

artstory.org

Individual pages work without javascript, search does not. Good for biographies and important works.

MoMA - The Museum of Modern Art

moma.org

The website of this gallery has a good repository of high definition images that can be extracted for a large number of artists.

in firefox:

Find art, ie https://www.moma.org/collection/works/104211, Ctrl+Shift+I (webdev tools), click on "Network" tab, click Reload. Click on the picture to make it larger. Look for the largest jpeg in the list. Copy its url.