In July 2016 the Senior Librarian of the Gennadius Library, Irini Solomonidi, spent a week at the "Institut d’histoire du livre" in Lyon where she attended a course on the study of incunabula, taught by Dr. Kristian Jensen, Head of Collections and Curation at the British Library. The course focused on the history of production of incunabula, which can be deduced by recognizing and carefully interpreting the evidence that the books as physical objects present us. This approach also provides us with some tools for recognizing books that have later been “improved” or even faked. By presenting the most important catalogues of incunabula in the historical context of their creation, the seminar emphasized their intended aims, as well as their strengths and weaknesses for specific current research purposes. The course also focused on illustration, lay-out and texts; and on the relationship between the various phases of production of incunabula and their end-users. Practical hands-on sessions involving real incunabula were held in the rare book and incunabula section of the Bibliothèque municipale de Lyon.