Galerie Aurel Scheibler, Cologne, 2004

The developments seen in Riley's paintings of the early 1980s had brought her to a point in 1986 where a further major redirection in her work was about to occur. In the spring of that year she introduced short diagonal forms to the vertical stripes. This brief period of work was very quickly transmuted into a new form that saw much larger diagonal shapes appearing on the canvas, breaking across the underlying vertical structure and counteracting them with the strong suggestions of movement and spatial recession. This form would be one which would occupy the artist for much of the next decade. The strong diagonal emphasis is suggestive of that found in the much earlier Cataract and Arrest paintings of the late 1960s, but whilst those works had concentrated on disturbing the perceived surface as one layer, the paintings of 1987 onwards ('zigs' in studio parlance) create a much greater sense of regression and progression, the diagonal forms suggesting that they both pass in front of and behind the vertical structure of the painting. This ambiguity of space, always a concern of Riley, is now developed further than in any previous works, the viewer now being less a spectator on the image being unfolded before them than an active participant in an image which constantly rearranges itself in a form that is virtually impossible to define.

The careful balancing and unbalancing of the forms in these paintings is controlled in such a way as to allow the image to constantly form and reform before the viewer and echoes both the artist's lifelong interest in the works of Piet Mondrian and the musical analogies that have so often been applied to her work.