The 1960s saw Martin continue to work with the grid in square paintings of 72 by 72 inches (183 centimetres). Room 5 features a selection of paintings in which Martin pencilled the grid in graphite or coloured pencil on painted canvases, blurring the distinction between painting and drawing. She used small amounts of paint and her pencilled lines are fine, assuming a subtle unevenness. Martin’s work was increasingly shown in group exhibitions, although her work was quite different to the impersonal and predetermined practices of minimalist artists with whom she was often compared at the time.

Throughout adulthood, Martin suffered from schizophrenia. These quiet and serene paintings were in fact products of personal and spiritual struggle, which she recalled later in her account of this period The Untroubled Mind. In 1967, she sold her possessions and left New York, embarking on an eighteen-month journey around the United States and Canada in a pickup truck and camper van. She abandoned art making for over five years. The reasons for this continue to cause much speculation. In a letter to Leonore Tawney, Martin wrote, ‘I must give independence a trial. I will have to have more time.’