For the past 27 years, he has been manipulating painted and photographic images by computer, developing a sophisticated and highly individual style. But the images have languished in his computer because, hitherto, the ink for inkjet-on-paper printing faded after only six months.
For this reason, other professional artists have tended to shun the inkjet, except for producing proofs for publishers. Hamilton, however, has kept on painting with his computer, while periodically telephoning ink and computer-printer manufacturers in Europe and America to ask whether they had yet discovered long-life ink.
His reward has been the development in the past couple of years of ink that will last for up to 36 years without fading and, in the last two months, ink with a 75-year non-fade lifetime. The breakthrough has suddenly given inkjet prints a commercial value, thrusting them to the forefront of printmaking - and coaxed from Hamilton's computer a couple of dozen of his finest images that are in a selling exhibition at the Alan Cristea gallery in London.
The colours of the new ink - called Equipoise and introduced by the Iris Graphics company of Massachusetts - though water-based (pigment would clog the microscopic holes in the stylus), are more light-resistant than watercolour, lithographs, or screen prints (serigraphs), familiar media whose light-resistance is seldom questioned.
Hamilton says: "Their quality would blow the watercolours that Turner used out of the water". Prints with the new ink have acquired a generic name of their own - giclee prints - derived from the French word for "to squirt".
Hamilton's work in the exhibition is, at first sight, a mile away from his notorious seminal image of 1956, the tiny 10in by 9in collage, Just What Was It That Made Yesterday's Homes So Different, So Appealing?, which, for the first time, put the word "pop" in the frame, amid a proliferation of images from advertising and industrial design.
The dogma and aggressive imagery has dissolved into a softer, more reflective mode. In his pastel-coloured A Mirrorical Return (1998) he used Quantel Printbox software to extract the image of a female nude photographed in the corridor of his home in the Chilterns, then ghosted it into the reflecting glass of a big picture frame, together with a scanned-in transparency of Bachelor Apparatus, a work by his one-time mentor, Marcel Duchamp. The space where the reflected nude should be standing is empty. The result is a dream-like trompe l'oeuil.
The muted colour quality of the earliest long-life ink is apparent in the first digital print he produced with it, Bathroom - fig 2, also of 1998, shown here. Having snapped his wife, Rita, wrapping herself in a bath towel, he popped her into the computer and manipulated the background into a Mondrian-like intersection of different coloured spaces.
Self-portrait With Yellow is Hamilton's attempt to "get paint into the computer". The original Polaroid photograph shows him looking through glass with yellow paint on it. More paint has been added electronically.
If Hamilton were producing Just What Was It... today, he would, of course, use digital imaging instead of cut-and-paste collage. He has restored the famous image by computer and printed an A3-size edition of 25 for the exhibition, which have sold out at pounds 750 each. An A4-sized edition of 5,000 that he printed for a BBC QED programme, issued free, attracted 75,000 applicants. That was before Equipoise ink: the prints are fading already.
The new ink was developed for Iris by the Lyson company of Stockport, at a time when Iris was the butt of an embarrassing media campaign by the big American art publisher, Colville, which complained that their ink faded too quickly. Colville have now announced limited editions of prints using Iris ink.
The foremost tester of the permanence of inks is Henry Wilhelm, founder of Wilhelm Imaging Research, of Grinnell, Iowa, who subjects ink-on-paper prints to accelerated fluorescent light at a temperature of 75F. His latest bulletin emphasises the importance of matching ink with the right paper for maximum longevity, and estimates the life of Iris's Equipoise ink at a maximum 32-36 years if used on Arches Cold Press paper, which has a subtle yellowish tone. On Liege Fine Art paper, it fades after only two-three years. No other ink lasts more than six years.
Meanwhile, Lyson has developed an even more light-resistant ink - Lysonic, which it launched themselves two months ago. One of Wilhelm's tests on it, using four different kinds of paper, has come up with 65-75 years on Somerset Velvet paper.
Lysonic can be used in printers considerably less expensive than the top-quality Iris that sells for about pounds 20,000. It is compatible with the Epson, which costs (ex-VAT) from pounds 190 for the Epson Stylus Photo 700, to pounds 1,1995 for the Epson Stylus Professional 5000. Breaking of the price barrier is bound to lead to an expansion of digital print-making.
In Carlisle, Massachusetts, this month, Peter Alpers, formerly on Iris's staff and now a consultant to the digital print-making industry, will launch Moonglow, the first art gallery specialising in giclee prints.
The earliest giclee prints are likely to become sought-after as pieces of art history. Hamilton's Marconi and Son, showing two figures in a sombre, Hopper-like interior, in an unusually small edition of 20, at pounds 1,750 each, is a 1998 version of the first image that he printed using an Iris inkjet printer - spotted at a 1994 trade exhibition. The printer itself delivered 300 dots per square inch, but the dots of ink exploded in such a way that they gave a continuous tone looking more like 2,000 dpi.
So far at the exhibition, it is museum curators, print connoisseurs and art historians who have been buying. Few are being bought for the office or mantlepiece. Traditionalists have muttered that the prints look like reproductions - perish the thought! - or commercial art. They will soon know better.
Exhibition prices: pounds 750-pounds 7,500. `Richard Hamilton: New Technology and Printmaking', until 23 December, Alan Cristea Gallery, 31 Cork Street, London W1 (0171-439 1866)