In 1962, Andy Warhol exhibited thirty-two small paintings which depicted almost identical cans of Campbell's Soup. The point of these paintings was to portray everyday, common, ordinary objects and to make people question the nature and function of art.
Art has been traditionally concerned with subject matter that is beautiful or unusual or inspirational. The Campbell's soup cans are in and of themselves not particularly beautiful, unusual, or inspirational, and are thus surprising, controversial subject matter for something that proclaims itself to be art. This made people question the assumption that art could not and should not be concerned with that which is purely functional or with the worlds of mass culture and commerce.
The Campbell's soup can paintings were produced by a screen printing process, which is a process first used to mass produce the same images onto fabrics. It is not considered a particularly difficult process and does not require too much of what might be called artistic skill. It is also a relatively quick process.
Traditionally, art is produced by methods which require tremendous skill and which take considerable time. Michelangelo took four years to paint the ceiling of the Sistine Chapel and two years to sculpt the statue of David. Leonardo da Vinci took four years to paint the Mona Lisa and three years to paint The Last Supper. Warhol's paintings of Campbell's soup cans, in contrast, would have been produced very quickly because of the screen printing process. This screen printing process was therefore another reason why these paintings made people ask, "Why is this art?" Indeed, for many people, something should perhaps not be considered art if it does not require great artistic skill or take a considerable amount of time to produce.