New York’s Metropolitan Museum of Art is making all public domain works in its collection available online for both scholarly and commercial purposes, it announced today. The new Open Access policy also introduces partnerships between the museum and Creative Commons, Wikimedia, Artstor, the Digital Public Library of America (DPLA), Art Resource, and Pinterest.
https://www.metmuseum.org/policies/image-resources
To identify these images, look for the Open Access icon, at the lower left of the image:

We’ve created 20 thematic sets of images to get you started: Masterpiece Paintings, Cats, Monsters and Mythological Creatures, Met-staches, New York City, Impressionism and Post-Impressionism, Winter Wonderland, Vincent van Gogh, The Pre-Raphaelite Style, Self-Portraits, Quilts, Gold, Georges Seurat, Arms and Armor, The Monuments Men at The Met, Faces from the Ancient World, Tiffany Glass, Dress to Impress, Art or Design?, and Dishes.
If an image for an artwork accompanied by the OA icon is unavailable on our website, please refer to the instructions for requesting new images below.