Book excerpt: Until recently, the phenomenon of copying in medieval book painting has been considered mainly in terms of the reconstruction of pictorial sources used for the composition or iconography of miniatures, initials, or decorative elements. Although historic sources only rarely mention the circumstances of manuscripts’ production, one particular widely-accepted hypothesis has prevailed until now, according to which artists used model drawings or sketch books with the aim of facilitating the production of copies and the creation of new picture cycles. However, it is no longer sufficient to regard medieval book painting in its diachronic dimension only through these lenses. Rather, one should consider Robert W. Scheller’s critique that “When using the model hypothesis one must always be mindful of other factors which are known to have played a part in the transmission of art in the Middle Ages”. The contributions of this volume deal with these issues by focusing on book painting between the 10th and 16th centuries.