Surface 210 (Superficie 210), 1957. Oil on canvas, 81 1/4 x 63 inches (206.4 x 160 cm). Solomon R. Guggenheim Museum, New York  58.1518. © 2012 Artists Rights Society (ARS), New York / SIAE, Rome

A decisive shift in Giuseppe Capogrossi’s career took place in 1949, when he moved away from figurative, tonal painting and experimented with an abstract geometric style that led to the development of a vocabulary of irregular comb- or fork-shaped signs. With no allegorical, psychological, or symbolic meaning, these structural elements could be assembled and connected in countless variations. Intricate and insistent, Capogrossi’s signs determined the construction of the pictorial surface. Similar to mysterious lists or sequences, his paintings were immediate in their appeal yet remained hard to decode, a quality he shared with other Art Informel practitioners. These abstract comb-sign paintings, known simply as Surfaces (Superficies, 1949–72), were first exhibited at the Galleria del secolo, Rome, in 1950. The comb sign dominated his oeuvre until the end of his career.