The hitherto neglected Pandechion epistemonicon, Ulisse Aldrovandi’s extant manuscript encyclopaedia, indicates that Renaissance naturalists did not necessarily apply the humanist jack-of-all-trades, the commonplace book, in their own field without considerably altering its form. Over many years the Italian natural historian tested and recombined different techniques to arrive at the form of paper technology that he considered to be the most fit for his purposes. Not all of these techniques were taught at school or university. Rather, Aldrovandi drew on administrative practices (...) as well as on the bookkeeping practices of early modern merchants that he knew first-hand. Reconstructing the formation and use of the Pandechion this article contributes to the historiography of learned reading and information management in Renaissance Europe. (shrink)