The commonsense principles of modern document design are direct descendants of the principles used in the Books of Hours, a hybridized religious instruction manual created in the commercial scriptoria of the 13th century. This article analyzes the design of Books of Hours and discusses how these medieval documents fit within the four design criteria (supertextual, extra-textual, intratextual, and intertextual) put forth by Kostelnick and Roberts [1]. The analysis reveals the early user of good document design features as the medieval scriptoria worked to address the audience and task requirements of the Books of Hours.