Focus on Mr and Mrs Clark and Percy and explore the Description.
The couple are depicted in the bedroom of their flat in Notting Hill Gate, near life size, either side of a tall window with a pair of shutters, one open to reveal the balustrade of a balcony looking out over trees to a Georgian façade beyond.  To the left, Birtwell stands in a purple dress with hand on hip; to the right sits Clark in green jumper and trousers, lounging on a modern metal-framed chair with his bare feet in the thick pile of a rug and a cigarette in his left hand, and with a white cat on his lap.  Both Birtwell and Clark are looking out at the viewer, drawing them as a third person into the composition.  The cat rebels by ignoring the viewer, looking out of the window instead.  
The room is relatively bare and uncluttered, in simple 1960s minimalist style, with a telephone and a lamp on the floor to the right of Clark, and a plain table to the left of Birtwell bearing a vase of lilies and a yellow book.  There is a framed print on the wall behind her.  
Hockney worked and reworked the portraits many times until he was satisfied, repainting Clark's head perhaps twelve times.  He has described the style of the painting as being close to naturalism, although the surfaces are characteristically abstracted and flattened.  Hockney achieves the difficult task of balancing the dark figures "contre-jour", against the light flooding in through the window behind them.  
The work is in acrylic on canvas, and measures 213.4 by 304.8 centimetres (84.0 in × 120.0 in) (or 217.0 by 308.4 centimetres (85.4 in × 121.4 in) in its frame). The painting was presented to the Tate Gallery by the friends of the gallery in 1971, and remains in the Tate collection. It featured in the final ten of the Greatest Painting in Britain Vote in 2005, the only work by a living artist to do so.
Notting Hill Gate naturalism canvas Tate Tate Gallery contre-jour Greatest Painting in Britain Vote minimalist