The Met Collection and Heilbrunn Timeline of Art History
Two resources from New York's Metropolitan Museum of Art that work best together. Since 2017 the Met has released images of its public domain works under CC0, more than 406,000 of them, and they are large, clean photographs that hold up on a classroom screen. Look for the Open Access icon on an object page to know you can download and reuse it.
The Heilbrunn Timeline of Art History supplies what a bare catalogue lacks: essays and chronologies written around works in the collection, so a learner can move from a single object to the period and culture that produced it. Few museum sites connect looking and reading this well.
