Since a single stock image library must be necessarily limited in the depth of it’s content, I have tried to compile a (hopefully) useful list of other sources which make visual material available to the general public.
If you search for photos and art which can be legally used for free, you may come to recognize that most websites either only provide very few images, i.e. the “free download of the day” (and in addition require registration), or distribute material with doubtful permission. Some of the major agencies offer a small selection of free photos, usually donated by a contributor (which are then used many thousand times by other designers). You may know these distributors already, so I did not include them here.
Do read the terms and conditions on each site before you start using the provided material. Many art galleries for example can not give a guarantee for each single picture, sometimes they are just believed to be in the public domain, and while the original artwork might be out of copyright several decades after the death of its creator, the digital version may have rights attached to it (i.e. a high quality scan which was cleaned and color corrected or otherwise altered / improved). Also, since copyright expiration time frames vary from country to country, you may have to acquaint yourself with the local regulations.
That out of the way, here’s the list of galleries. Many are a pleasure to visit just for the sake of viewing the art, and usually that’s the main purpose of these collections:
The National Gallery of Art. I’m linking here to a page which explains their open access policies, and perfectly illustrates the points made above.
https://images.nga.gov/en/set/show_content_page.html?category=16&set=11 gives you access to many works by Van Gogh, Monet, Gauguin or Renoir, and you can navigate further from there. Download size of “lecture images” is 1200 pixels wide.
Getty Open Content Program: http://www.getty.edu/about/opencontent.html
Here The Getty makes all images available to which they hold the rights or which are in the public domain. There’s no charge and no permission required. You have access to about 100,000 images from the Getty research Institute and the Getty museum, which includes photographs, drawings, paintings, sketches and architectural works from five centuries. Available images are marked with “This image is available for download, without charge” underneath and served in different sizes, from 1024 pixels wide to >4000 pixels, which allows for printing. Take note of the attribution requirements and the Fair Use policy.
The Yale University Art Gallery makes several thousand images available for free download. Note that not every work of art is free of restrictions. Presentation size downloads are about 1900 pixels wide. Full size downloads, when available, are protected with a Captcha and come in TIF format. High resolution file dimension is 3000 pixels wide, created with Phase One P45+ devices.
The Metropolitan Museum in a new initiative, announced in spring 2016, provides access to more than 400,000 digital files. Before images were provided upon request only, and for a fee, now it allows downloads for NON-COMMERCAL USE.
The British Museum makes an increasing number of their collection available for NON-COMMERCIAL USE. Higher resolution files (2500 pixels wide) or commercial use require registration.
The British Library recently put about 1 Mio. images into the public domain, accessible via https://www.flickr.com/photos/britishlibrary/ under Flickr Commons for anyone to use. These are mostly scanned book pages from three centuries.
Many museums and art galleries are now on the move to open their collections. http://open-collections.okfn.org/ not only references free image archives, but also cultural heritage, rare books, natural history, textiles, theatre and music.
A number of other galleries and museums, notably. the Rijksmuseum of The Netherlands, have enabled downloads and the acquisition of prints via a registration model.
For contemporary art, visit the author’s print gallery.