Defined by perceptual and intellectual dilemmas, Denny’s paintings throughout the 1960s sought to explore space and modes of perception via lines and bands of colour. The works would often be exhibited in unorthodox ways, such as set unframed and directly on the floor, challenging the traditional understanding of pictorial space. Denny’s radical exploration of this subject continued for the entire decade, the resulting work demanding a constant process of visual adjustment from the viewer, with space becoming an ambiguous mental construct. The artist’s work of this decade was widely and critically acclaimed, according to critic David Mellor it resulted in ‘some of the most accomplished abstract paintings made in Britain in the twentieth-century’. Following a structure typical of Denny in this period, the present example features symmetrical linear structuring around the central, portal-like form, reflecting Denny’s enduring interest in ancient architecture and geometry. Despite this strict linearity and emphasis on verticality, there is a human element with the focal point appearing door-shaped, Denny almost suggests the viewer could step inside, indeed he would often hang these works six inches from the ground further indicating his intention.