This reproduction of Ellsworth Kelly's 1954 <i>Sketchbook 23</i> offers a rare glimpse into the celebrated artist's rigorous exploration of line, form and composition. Drawn into a blank book and forming a single continuous gesture over 25 pages as the artist saw and captured the changing fall of shadows while riding on a bus in Paris, Kelly's line pursues a path of eccentric discovery and distillation through subtle variations and bold transformations.