E-readers have been available for many years, yet many people are still hesitant towards reading digitally in their spare time. In previous studies in the field of Human-Computer interaction (HCI), new e-readers have been designed, e-readers have been evaluated, and the attitude towards digital reading have been studied. The need to look at books from a larger perspective have been identified, to understand what properties desirable e-readers should have. Now, e-readers almost exclusively let users read books but fails to enable other actions that paper books allows. In this study, to allow for an analysis of books in different contexts and what roles books play in those contexts,DeLanda’s assemblage theory have been used. The research question this thesis answer is: what material and expressive properties of paper books are important in different contexts and how should these be implemented into e-reader? The study followed an ethnographic approach by collecting data from interviews with eleven book lovers, at home observations, and public observations in places where books were present. From the gathered data, ten assemblages were identified and four of them, namely ‘Evening with friends in the living room’, ‘Time for bed’, ‘Let time fly by during the flight’, and ‘Browsing the library’, were described in depth. After identifying what material and expressive roles of paper books were important in these contexts, seven implications for design of e-readers were presented. Inconclusion, aspects that should be implicated into e-readers are ‘Travel compatible’, ‘Reminding’, ‘Personalized organization’, ‘Display collections’, ‘Encourage nostalgia’, ‘Provide inspiration’, and ‘Security and continuity’ to accommodate for the goals users have when using books in different contexts.