The work of the American painter Jackson Pollock speaks to us not only through exhibitions of paintings hung on gallery walls, but also through the films and photographs [1] of Hans Namuth which exposed Pollock's phased working process to the public. In the first of two distinct phases Pollock is seen immersed in, and in intimate interaction with, a large horizontal canvas. This records traces of his movement and expressive gestures in heterogeneous media. A second phase is then triggered by a pivotal operation: the horizontal recording and working surface is transposed to a vertical viewing plane. Leo Steinberg recounts that Pollock: ‘would tack the canvas on to a wall – to get acquainted with it, he used to say; to see where it wanted to go. He lived with the painting in its uprighted state, as with a world confronting his human posture’.