John Dee's Monas Hieroglyphica (1564) was a work which involved a close collaboration between its author and his "singular friend" the Antwerp printer Willem Silvius, in whose house Dee was living whilst he composed the work and saw it through the press. This article considers the reasons why Dee chose to collaborate with Silvius, and the importance of the intellectual culture - and the print trade - of the Low Countries to the development of Dee's outlook. Dee's Monas was probably the first alchemical work which focused exclusively on the diagrammatic representation of the alchemical process, combining diagrams, cosmological schemes, and various forms of tabular grid. It is argued that in the Monas the boundaries between typography and alchemy are blurred as the diagrams "anatomising" his hieroglyphic sign (the "Monad") are seen as revealing truths about alchemical substances and processes.