Site: http://collection.imamuseum.org
Conditions: Free images available but hard to find.
The official line is:
‘Many images of public domain artworks are available for free download from the Indianapolis Museum of Art at Newfields’ collection pages. Simply look for the download icon to access a high resolution JPG file and begin using the image for any purpose. If you require a high quality TIFF file for your publication or product, please complete the Image Request Form‘
However, the search interface is clunky, doesn’t allow date specific searches, or an easy way to tell if an image is going to be free or not. You have to click on each image to see if there is the download icon, or if it says ‘Image Licensing’. The alternative is looking through Useum’s site for the museum which has pre-edited all the free ones, although this is not searchable or refinable in any way.
Source: https://discovernewfields.org/research/image-resources
Free Academic Images 