Architecture and freehand drawing are inextricably linked. Even in the Gothic period, the principle applied: what you can't build, you at least draw. The same applies to the sketches of Wolf dPrix, co-founder and CEO of Coop Himmelb(l)au. Over the 53 years of their creation, Prix's sketches formed the first stage of every design – despite rapid developments in digital architecture. Whereas his freehand drawings were proxies for completed projects in the 1960s and 1970s, today they serve as strategic guides to the firm's complex buildings. From 2,800 archival drawings, 1,300 examples were selected for publication to represent developmental dynamics in an archive-like format. As invaluable documents of architectural history, they illustrate some 320 selected projects.