Using copyrighted material should not be a substitute for creative effort. Your goal should be to understand and demonstrate how the use of a copyrighted work repurposes or transforms the original. For example, you may use copyrighted music for a variety of purposes, but cannot rely on fair use when the goal is simply to establish a mood or convey an emotional tone, or when they employ popular songs simply to exploit their appeal and popularity.
Use language, images, sound, music, and digital media to express and share meaning with an emphasis on transformative uses such as comment and criticism, illustration, stimulating public discussion, or preserving an event or phenomenon.
The Fair Use Evaluator is a tool that can help guide you through the process of making a reasonable fair use determination.
Art UK
Collection of 200,000+ oil paintings from local and national museum collections in the United Kingdom. The site is a joint initiative between the BBC, the Public Catalogue Foundation, and participating museums and collections.
British Museum
Use Search box or Advanced Search options, limit to objects with images online.
Searchable online collection of art from the Metropolitan Museum of Art in New York.
Musée du Louvre, Paris
Atlas est une base qui permet de consulter l'ensemble des œuvres exposées dans le musée, soit près de 30000 oeuvres. (Interface is in French.) Try using "Recherche simple" for artist name.
Contains 76,000+ works from the MoMA, all available online and enhanced search filters.
National Gallery, London
Use search box or other options available
National Gallery of Art, Washington D.C.
Use search boxes to "Search the Collection"
Rijksmuseum
One of the world’s leading museums in Amsterdam has a ground-breaking new online presentation of 125,000 works in its collection.
Smithsonian Institution
Search over 13.3 million records of museum objects, archives and library materials including more than 2.5 million online media files.
Tate Modern
A high-quality collection of images that have been tagged with descriptive qualities like "hope," "nature," or death." Find an individual artwork and scroll down to EXPLORE at the bottom of the record to find links to other images, concepts or topic
Reverse image searching allows you to upload an image and retrieve other similar images. Use this technique to:
There are many systems that offer this service; here are two good ones: