Turnbull is best known as a sculptor, but also produced paintings throughout his life. Towards the end of the 1950’s he was looking for ways of painting in which the viewer’s experience of the work should be as direct as possible and not constrained by secondary associations. He began to make the surface of his paintings very smooth, in contrast to the gestural, textured works he produced in the mid 1950’s. His aim was to produce a single colour surface without making shapes or compositions.