The work with which he announced this style was Onement I (1948, MoMA, New York), a monochromatic canvas of dark red with a single stripe of lighter red running down the middle. Such stripes (or ‘zips’ as he preferred to call them) became a characteristic feature of his work. By the time he painted Onement I Newman already had a reputation as a controversialist and a spokesman for avant-garde art (in catalogue essays and articles in journals), but he had a hard struggle to make his name as a painter. His first one-man exhibition, at the Betty Parsons gallery in 1950, was coolly received by critics and fellow artists (only one work sold—to a friend of his wife's), and by the mid-1950s his very spare style had separated him from the predominantly gestural idiom of his colleagues. For a time he became a somewhat marginalized figure and he stopped painting in 1956. He had a heart attack in 1957, but in the following year a resurgence began with a series of paintings in black and white, and in the last decade of his life his output and his reputation soared. In the 1960s he began making steel sculptures featuring slender shafts recalling the vertical strips of his paintings (Broken Obelisk, 1963–9, MoMA) and in his late years he also experimented with shaped canvases, painting several triangular pictures.