In the Spring of 1631, the Swiss physician Théodore Turquet de Mayerne (1573-1655) wrote to Peter Paul Rubens (1577-1640), thanking him for the ‘excellent tableau’ Rubens had sent him (Pl 1). The year before, in London, Mayerne had sat for Rubens and the watercolour Rubens then made provided the model for the portrait Mayerne now received. During the drawing session, Mayerne might have asked Rubens about his artistic techniques, a subject in which he took a great interest. The result of that interest is still traceable in a manuscript in the British Library, known as ‘the Mayerne Manuscript’ or by the title Pictoria, sculptoria et quae subalternarum artium. From 1620 to 1646 Mayerne collected an impressive amount of recipes and notes, in a variety of languages, on the techniques of art, from painters, miniaturists, goldsmiths, apothecaries and artisans of varies kinds. Most were written on loose leaves of various sizes, eventually bound together in the manuscript we have today.