Its origins are complex and include Cubist collages with real newspapers or cane seats; Picabia's 'object portraits'; brand-name wafers used by Picasso in 1914; biscuits and matchboxes used by Chirico in 1916—17; Stuart Davis; the Surrealists' found objects of the 1930s; the ready-mades of Dada, in particular of Duchamp; Leger's flat, impersonal handling, which extolled machines, and his enthusiasm for window dressing, or the plastic quality of manufactured objects, as materials for artists; Bacon's use of photographs; Cinerama, television and the wide-screen close-up as prototypes for environmental art and the huge-scale detail; the composer John Cage's distinction between accidental and chosen sounds transferred to art, since the artist may be inspired by casual combination of forms or by the deliberate selection of commonplace and cliche aspects of life, and actions may themselves become works of art, as in 'happenings', although these tend to be more destructive than constructive, and are certainly ephemeral.

Two independent streams are discernible. The English stream came first, during the 1950s (the writer Lawrence Alloway appears to have coined the term Pop Art about 1955/6), the main originating artists being Paolozzi, Richard Hamilton and Magda Cordell, laterjoined by a second wave including R. Smith, Wm Green, Roger Coleman, Wm Denny and Peter Blake; a third wave includes Barrie Bates ('Billy Apple'), Derek Boshier, David Hockney, the American R.B. Kitaj, P. Caulfield, N. Toynton, Allen Jones and Peter Phillips, although this wave also contains artists notably more subjective in approach, with overtones of the erotic, the romantic, and the optical illusion (leading to 0p Art).

American Pop Art appeared mainly in the 1960s and is more dependent on Duchamp. It uses hard-edge techniques and colours of commercial-art origin (but never of the glossy-magazine type, only of billboard and cheap journalism), collage, and assembly of objects. It is rarely romantic, often humorous, sometimes macabre or scabrous, always close to its source in artefacts and unsophisticated mass-media. Its chief protagonists are Andy Warhol, Lichtenstein, James Rosenquist, Wesselmann, 0ldenburg, and its originators (who are less strictly Pop than their successors) are Jasper Johns and Rauschenberg. In California, its other main centre, it could have developed independently of East Coast forms, as a reaction against Abstract Impressionism, which was East Coast in origin, but had swept all before it across the Bay. The formative influence was Kienholz, whose assemblages of detritus, arranged anecdotally, seem to point a bitter allegory on the nastiness beneath the glossy surface of modern urban life. In such artists as Bengston, Mel Ramos, Wayne Thiebaud and Ruscha, it developed rapidly and quite differently from the East Coast branch. One of the characteristics of much of Pop Art is that it is suitable only, and appears to have been designed only, for museums and the like. Few private collectors could expect to house rooms of bizarre furniture, or giant plastic pouffes such as Oldenburg makes, or Marjorie Strider's 10-foot striped styrofoam clouds hanging three deep from the ceiling. In this it resembles much of Abstract Impressionism, which also tended to produce pictures from 6 to 17 feet in size, as if scale were the only measure of content.