This account examines the format and style of book illumination, explaining the basic vocabulary and concepts that are needed to understand this art form. The author offers insights into the fundamental philosophy, theology, technology and cultural ambience underlying the production of book illumination throughout its history. Exploring the relationship between script and decoration, image and frame, surface and space, the book aims to shed light on new aspects of the art. Illustrated with examples ranging from late-antique roll illustration to Renaissance miniatures, this study also includes a select bibliography of Pacht's works.