Smithsonian's Open Access now has over 4 million free-to-use images

Caracal. Photo: Jessie Cohen, Smithsonian's National Zoo (public domain)

If you need to use an image for your art, product, project, or any other reason, check out the Smithsonian's vast collection of Open Access images available under the Creative Commons Zero (CC0) license. I searched "cat," and it returned over 7,000 images, and every one I looked at was terrific.

Head of a Cat. Smithsonian American Art Museum, Gift of Mrs. Armistead Peter III
Sand Cat. Clyde Nishimura, FONZ Photo Club
Honorable Mr. Cat. Smithsonian American Art Museum, Gift of Hyde Gillette in memory of Mabel Hyde Gillette and Edwin Fraser Gillette
Cat from a Ball Toss Game. Smithsonian American Art Museum, Gift of Herbert Waide Hemphill, Jr. and museum purchase made possible by Ralph Cross Johnson
Cat and kitten. Gift of Anonymous Donor
Cat in Eakins's Yard. Hirshhorn Museum and Sculpture Garden, Smithsonian Institution, Washington, DC, Gift of Joseph H. Hirshhorn, 1966
Wild Cat and Turtle. Smithsonian American Art Museum, Gift of J. Willis Johnson