Over her long career, O’Keeffe revisited and reworked the same subjects, developing, repeating, and transforming motifs that lie between observation and abstraction. Between 1915 and 1918, a breakthrough period of experimentation, she made as many works on paper as she would during the next four decades, producing progressions of bold lines, organic landscapes, and frank nudes, as well as the radically abstract charcoals she called “specials.”