And so to hang a Caulfield in an art gallery, a gallery moreover where all the other objects around it are themselves other pictures by Caulfield - obviously, the effect will be lost. You'll get a total neatness stalemate. Or some of the pictures will even start to look, by comparison, a bit messy.
This is just bad luck. A retrospective is the standard way of honouring an artist of Caulfield's years and achievement. There are nearly four decades of painting on show at the Hayward Gallery, and his name has been famous for most of them. It's bad luck that his pictures aren't designed for their own company.
Their un-retrospect-ability needn't reflect badly on them, though. Caulfield's art requires a quasi-domestic, non-art environment to work in - and this is an interesting thing about it. But, of course, that's likely also to mean a privately-owned environment. (Leaf through the Hayward's catalogue, and note which pictures are in private hands: those are the Caulfields in proper homes.) So what about public honour? And public access?
Good questions. After all, Caulfield is something of a public favourite, a one-time "pop" artist who really was. In his mid- twenties, in the early Sixties, he invented a style that became proverbial. An advert could use it, confident that most people would recognise it, even if they couldn't name its creator. A bit of Leger, a bit of Mondrian, a bit of Minoan fresco and commercial illustration combined to produce the most distinctive British graphic since John Flaxman's neo-Greek outline drawings two centuries ago. And like Flaxman's plain penmanship, the Caulfield manner wasn't exactly personal.
A thick black line, always of the same, steady thickness, defines each object and detail. It's a style that stresses and isolates things; or rather, insulates. It's a world made snug; outline as lagging. It's also a world made equal. Whatever is described gets identical treatment, and this can have funny results. Very small and thin things - a stem, a bit of grit - are established with outlines thicker than themselves.
In fact, the charm of this Sixties style is its perfect insensitivity. It's as if some original picture - with a wide, various and responsive range of marks - had been put through a programme that recognised only one sort of line. Sometimes Caulfield makes a pointed joke about what's lost in this translation. In View of the Rooftops, say, or in Bend in the Road, you find some single, separate little squiggles. They're evidently meant to stand for cracks in the brickwork, or divots in the ground, and you can see that in a more responsive style that's what they would mean. But here, with their even widths and square ends, they're as blankly non- descript as a road-sign. They deliberately strain depiction.
At the same time, this world of even, definite edges is filled in with floods of even, luminous colour, which always stops clean at the outlines, but often spreads over individual things. In Dining Recess, a whole room with its table and chairs is blocked in with a uniform grey - a scheme that's only broken by a large spherical lamp (bright warm white) and a window of evening sky (dull violet). So while the outlines stress separate objects, the colour can override this, asserting (contrarily) large units of sameness. This is playful and mysterious. Also, through sheer arrangement of flat colours, Caulfield can introduce not just luminosity but a sense of realistic lighting - oddly, as these images are, of course, without any directionalised light and shade.
So: a world made clear and strange, formulated, set at a remove, straining at the real. And the best work that Caulfield made in this style, it seems to me, the work that turns its economies to maximum impact, is not a painting, and so not in this retrospective. It's a book-work of 21 screen-prints that obliquely illustrate poems by Jules Laforgue. But you hardly need the poems to get the point. The images' strength is in their smallness, their close-croppedness, and that they're a series.
They show a life in cut-off details: a glimpse of sky through parted curtains; a menu card; a bedside lamp; railings; a clock; a glass of water on a window sill. They're details whose very inconsequence is poignant. They're the kind of minutiae that, in extreme emotion, the mind lights on, latches on to, holds for always - the kitchen tap that will emblematise for ever the first night or the last row. This is the subject Caulfield's detached intensity was made for. You can see a set of these prints in a general retrospective of Caulfield prints at the Alan Cristea Gallery in Cork Street. Or there's another set that's going round the country as a Hayward Gallery Touring Exhibition, and it can be seen at the Howden Park Centre in Livingston, West Lothian, from next week.
One thing these Laforgue images do is answer a question that Caulfield's images often leave begging: why? Why is he so interested in this world of contemporary and slightly tacky accessories, design, and cuisine? What do these objects and environments mean to him? Are they just the kind of things he paints? It looks increasingly like that, just as his paintings as time goes on seem more and more to be ways of - very elegantly, very intelligently - filling up a canvas.
The Caulfield style of the Sixties was, as I say, not exactly personal. It suppressed his individual handwriting (though not quite entirely; that was another of its vital tensions). It was certainly very consciously adopted. And for all its seeming uniformity, it was capable of considerable play. So why not adopt a few more styles, and mix them together, and generally up the gamesmanship? That's been Caulfield's course since the mid-Seventies.
He's developed a repertoire of depictive devices and accomplishments. There's outline-less silhouette, and very high-finish photo-realism, and a looser, more impressionistic photo-realism, and exact imitations of patterns and textures (wallpaper, woodgrain), and flat shapes which mean cast shadows, or patches of cast light, or sometimes just an abstract shape. And there's some low relief too. All these things intersect and overlap to create different levels of reality and trompe l'oeil effects and elusively paradoxical spaces.
True, this variety act never becomes stupidly show-off. It's really quite tactful. On the other hand, it doesn't seem very pointful, and I admit I was finding it hard by the end to keep my eye on them. But they're still as neat as can be, and perhaps the real problem is public exhibition. Seeing them in relation to the surroundings of a more private setting might make all the difference. As for public access, there's a simple answer - posters, large and high-quality reproduction, with wide distribution. Take one home: that's the best retrospective this sort of art could ask for.
Patrick Caulfield: Hayward Gallery, South Bank, until 11 April; pounds 6, concs pounds 4. Print Retrospective: Alan Cristea Gallery, 31 Cork Street; tomorrow to 11 March; closed Sat pm and Sun; free. The Poems of Jules Laforgue: Howden Park Centre, Livingston, West Lothian; 18 Feb to 11 March; closed Sun; free. Then touring to Brecon and Taunton