I just came across the free public domain image collection at Raw Pixel. You can download high res files of these vintage images for personal or commercial projects. The images are available to all under a CC0 License. There are lots of places to find public domain images online (the New York Public Library, for one), but I like the big thumbnails and simple layout of this growing collection.
If you follow my work, you know I love patterns. I enjoy these from Japanese designer and painter Furuya Korin (1875–1910).
