The protruding area to the right of the canvas in Viewer, as well as the vertical interruptions punctuating the work, create a strong sense of depth; Boshier is artificially forcing a two dimensional medium to escape its confines and enter a new dimension, much like the stereographic slide viewer toys to which the work may refer. The work is full of this sense of rebelling against old constraints and breaking new ground. This was an important period for Boshier as he increasingly turned to geometric abstraction with shaped canvases and Op Art overtones, although the inclusion of mass culture detritus such as distorted TV static and toys locates the present work in a more transitional phase. In the wider context, the piece captures the optimism but also the rebellion and anxieties of ‘Swinging London’ in the early 1960s. The rainbow symbols may allude to the Campaign for Nuclear disarmament and the anti-nuclear Aldermaston marches, in which Boshier participated. Their shape is reflected in arrangements of concentric grey circles reminiscent of the view down a gun barrel, or diagrams of a nuclear blast radius.