There are a number of possible explanations for this linguistic oddity, the most likely being that Clough sees in the word "retrospective" some intimation of an end. Since she is still working actively - sufficiently so to have been shortlisted for this year's Jerwood Painting Prize - her aversion to any such suggestion seems fair enough.
Since painters are in the business of creating surfaces, this has made for an interest-ing tension in Clough's work. From the earliest picture in the show - a small panel called Shore Scene (1941), heavily influenced by English Surrealism and painted when the artist was 21 - Clough's work has been obsessed with the unearthing of some kind of artistic truth. From the 1940s to the 1960s, this involved her working in what might loosely be called a social-realist manner: painting gritty things like mines and coke yards in a sooty palette of greys and blacks. Look at a picture like Man Under Catwalk (1957), though, and something else becomes apparent. Although the work is broadly representational, Clough's style is already busy breaking itself down into abstraction. Catwalk grids dissolve into a geometry that represents nothing at all; colours appear for their own tonal sake rather than to illustrate something else.
Somewhere in this process, you feel, Clough began to ask herself questions about the morality of representation. This questioning didn't simply have to do with whether her paintings should be figurative or not. It seemed to ask whether she was right to be painting them at all.
Take Wasteland, painted in 1979. As its name suggests, the painting's preoccupations are urban. Three grey blobs suggest the map of a traditional city, the curvilinear street plan of which forms the grid from which the blobs are made; on top of these are superimposed jarring bars of matt black paint. The effect is like a Corbusian town planner's blueprint, the discord between the blobs and bars suggesting the imposition of a new (and apparently brutal) modernist cityscape on something older and softer-edged. So far, so socially conscious: but something else is also going on in Wasteland. The painting's sense of threat does not come simply from its being a portrait of modern urbanism. It also comes from the visual language - the code of symbols, bars and blobs - used to paint that portrait. The use of cartographer's symbols suggests that Clough's painting has somehow become complicit in the thing it is trying to portray; that representation can be as guilty as the subject represented. If Wasteland is about social consciousness, it is also about the morality of being a painter.
Bound up in all of this is a sense of what may be thought of as the geology of painting. If the use of coded signs and symbols suggests the telling of dark secrets, then the process of putting paint on canvas also involves a cover-up. Wasteland is about stratification on two levels. First, its subject is the burial of old things under new ones; then it is about the burial of canvas under paint, or of layers of pigment under other layers.
Clough's obsession with this idea of burial becomes obvious in pictures like Small Gate Painting 1, also dating from the late 1970s. In the 1950s, she painted mines: now her work begins to mine itself. Small Gate Painting 1 is a canvas of a canvas, the portrait of a portrait. With jagged, trompe-l'oeil-ish tears around its edges and more black bars slashing through the fabric-coloured pigment Clough has painted over her real canvas, the picture sets out to expose its own deceitfulness. Ten years later, and we might have thought of Small Gate Painting 1 as being Post- Modern. It is nothing as slick as that, though. Clough's painterly soul- searching is intensely (sometimes violently) personal rather than fashionably self-deconstructing. The false slashing of her false canvas seems to have less to do with introspection than with self-evisceration.
The most striking thing about the Kettle's Yard show is the sense of inevitability it suggests in Clough's progress. Her latest pictures seem the only possible end to her 60-year journey as an artist: they have become both a portrait of the thing and the thing itself. A painting like Emerge (1996) is art and geology at the same time, its granite surface scratched and striated to reveal a patch of Bridget Riley-ish stripes. The picture seems to work backwards, from underlay to finish in a reverse excavation of the process of painting. Two works, Land: Ochre (1998) and Land and Shale (1999), have an especially tectonic feel to them. The latter can be read in two directions; both horizontally, as a map of geological strata, and three-dimensionally, through the paint surface and implied picture plane and into the canvas itself. The violence and self-doubt of the 1970s have gone from these works, leaving them older, more romantic, almost monumental in feel. They seem so complete in themselves that it is hard to imagine where Clough could possibly go from here. You can only look forward to her next non-retrospective to find out.
'Prunella Clough': Kettle's Yard, Cambridge (01223 352124) to 26 September. Jerwood prize announced 21 Sept, Jerwood Gallery, SE1 (0171 654 0171), exhibition 22 Sept-24 OctReuse content