The picture posed great technical problems for Hockney. It took him nearly a year to complete the painting: 'I kept taking photographs, making drawings, trying to work out a composition; for these big paintings I worked out the composition before I began, although I didn't draw them out totally. They're often drawn with a brush.' (Stangos, p.203.) This squared-up study shows the couple placed before slightly shuttered full-length windows. The figure of Ossie Clark had formerly been larger in proportion and the head set upright. The artist superimposed a sheet of paper over the figure and redrew it.
Hockney wrote, 'it's odd that Ossie is sitting down; it should really be the lady who's sitting down, but Celia's standing up. That alone causes a slight disturbance' (Stangos, p.204). He said that he did not suggest the reversed pose but that it was the way the couple naturally placed themselves. Birtwell's pose is more relaxed than in the finished painting. Although in the same position as in the painting, she hides much of the shutter behind her. Clark sits up straight across the side of the chair, one arm on his hip, the other flung over the back of the chair. He wears a light flowered shirt, which contrasts with the dark tones of Birtwell's dress. In the painting he wears a sweater over the shirt. The relaxed poses of the two figures are reversed for the painting. Birtwell takes on an almost columnar pose, Clark slouches in an armed chair, a white cat in his lap.
Shortly after its completion in 1971, the finished portrait was displayed at the National Portrait Gallery, London, together with all the preparatory drawings and photographs. The Tate owns two other studies for the painting (Tate Gallery T01515-16).
Nikos Stangos (ed.), David Hockney by David Hockney, London 1976, pp.23, 197, 203-4, 239Marco Livingstone, David Hockney, revised edition, London 1987, pp.131, 136-7, 159