American painter Frederick Hammersley (1919–2009) is best known for his hard-edged geometric abstractions. However, their elegant simplicity belies the complex system behind their creation. Thanks to sketchbooks, notebooks and color swatches reproduced in this catalog, the artist’s beautiful documentation of his multistep way of working out compositions is on full view. These artworks and archival materials show that rather than an all-at-once creative act, Hammersley’s method was step-by-step and structured by rules. Essays by Alan Phenix, a conservation scientist, as well as by Kathleen Shields and Nancy Zastudil, who manage the artist’s foundation, bring to light new scientific findings about his paintings.