Stock photography is the supply of photographs which are often licensed for specific uses. The stock photo industry, which began to gain hold in the 1920s, has established models including traditional macrostock photography, midstock photography, and microstock photography. Conventional stock agencies charge from several hundred to several thousand United States dollars per image, while microstock photography may sell for around USD 25 cents. Professional stock photographers traditionally place their images with one or more stock agencies on a contractual basis, while stock agencies may accept the high-quality photos of amateur photographers through online submission.