This article explores the relationship between skin, materiality and medicine in the early modern German-speaking lands. It focuses on the understudied artwork of the Munich-born artist Johann Rottenhammer (1564–1625), demonstrating that his painted bodies were related to medical understandings of skin. Skin was a mediating boundary between inside and outside: the colour and texture of skin carried meanings about the internal state of the body. In this period, ‘exploration’ beyond Europe was destabilizing the definition of ‘good’ or ‘normative’ skin. The appearance of healthy or unhealthy skin was expressed in contemporary northern European artistic theory, for example in Karel van Mander’s Book on Painting. This article contributes to the growing literature on materiality and medicine by demonstrating their indelible impact on the artist’s project. Medical histories of the sixteenth century have traditionally positioned the Galenic and Paracelsian medical traditions as diametrically opposed. This article observes, however, key areas of similarity—the origin of curative materials, and the relationship between the internal body and the external natural world—and considers how they were present in early modern German understandings of skin.