Gallery-goers are flooding into the show of pop art stalwart Roy Lichtenstein at the Hayward Gallery, helping to canonise this chapter in art history. Meanwhile, the US big hitters of Pop have taken pole position in the sale rooms. The collectability of pieces by Claes Oldenburg, James Rosenquist and Ed Ruscha has soared in recent years. Andy Warhol has become one of the most expensive late 20th-century artists, with Jasper Johns and now Lichtenstein close behind.
But what of that other key strand in Pop Art - the home-grown variety? From the 1950s to the 1970s, British artists created a parallel pop strand that similarly derived its imagery from mass media, advertising, photography, comic strips - Pop Art, in Lichtenstein's phrase, being "the use of commercial art as subject matter" - and yet retained a distinct flavour, both critical and celebratory. Indeed, many argue that British Pop came in advance of the American strain with Richard Hamilton defining the credo and British critic Laurence Alloway coining the phrase in 1958.
These points are made in an upcoming exhibition in Italy called "Pop Art UK: British Pop Art 1956-1972". It will show 60 works by key UK pop artists, from early progenitors Hamilton and Eduardo Paolozzi, through to the "RCA Group" - Peter Phillips, Allen Jones, David Hockney, R B Kitaj, Patrick Caulfield, Derek Boshier and Joe Tilson.
There have been few such group shows, says curator Marco Livingstone, the authority on British Pop Art and author of Pop Art: A Continuing History (Thames & Hudson). "There have been shows in Hamburg and in Bilbao, but this is the first group show of any scale," he said.
Could this underline a sense that British Pop Art has become fashionable? After all, the restaurant The Ivy has images by Tilson, Caulfield, Sir Peter Blake and Jones on its walls, and pop millionaires such as the Gallaghers have bought work by Blake. And Tate Britain's show this June, "Art and the 60s: This Was Tomorrow", is to feature Hockney, Blake and Hamilton. Although it doesn't sort British Pop separately, the art market tracker AMR (www.artmarketreport.com) shows a clear lift in international Pop Art prices in the last two years.
Mr Livingstone is cautious. "People have been talking about the revival for so long that I'm not sure it has never been out of fashion," he says. "But it's true to say that it's more expensive than ever. Early pop prints that were up for auction at Christie's recently had teasingly low estimates and went for way over."
Even so, Mr Livingstone says that British pop artists do not sell as a body of work. "It's more sensible to talk about them as distinct from each other," he says. "But most of the British artists are very undersold compared to the Americans, with the notable exception of Hockney." (He has become a kind of honorary American, with prices to match.)
He says: "The only British challenger is Richard Hamilton, although Allen Jones has a pretty solid market even though he hasn't had a regular gallery for a long time. And Caulfield - who is one of the great painters - has become more expensive since being bought by Saatchi and since his retrospective at the Hayward Gallery." His prices are still a tenth of Lichtenstein's.
Meanwhile, some British pop artists can be bought for reasonable sums. Livingstone won't say who they are for professional reasons, but artists like Richard Smith, Clive Barker and (early) Robyn Denny may be among them, and their work is ready for a market reappraisal.
"Certainly, British artists are undervalued compared to US artists," says Alan Cristea. His gallery has sold original pop art prints for 30 years - its current exhibition is Roy Lichtenstein and Andy Warhol, to coincide with the Hayward show. "You can't say that you'll get a bargain buying a British pop artist because no one knows what the future brings. …