Chapter 4 considers the complexities of how to judge paper, and paper’s affordances in making books. The chapter begins by surveying the writings of some medieval commentators on paper, from Peter the Venerable, through the Italian humanists, to the late-medieval English Paston family in their letters. This chapter then considers the variety of books written on paper and the problems associated with the interpretation of their value. It is all too easy to classify paper books as being of lower status, lower quality and ephemeral intent. Paper had a multiplicity of potential uses. The arguably aesthetic hierarchies often applied to paper manuscript production do not take into consideration the quality of paper, nor the different types of paper in circulation. This chapter considers how the differing sizes of paper work together in book production. I also return in this chapter to the question of choice, exploring whether, in the current state of research in medieval book production, scholars can find an alternative way of describing differences between materials and artefacts which does not involve judgements about superiority or status. The chapter argues for a more nuanced understanding of paper codices.