Dietterlin’s Architectura prints and the processes he used to form them engaged with sixteenth-century Central Europe’s robust culture of alchemy to transform the architectural image into a context of scientific inquiry. Formal and iconographic analyses of architectural etchings by Dietterlin, Wenzel Jamnitzer, and Hans Vredeman de Vries, in conversation with texts by alchemists Agrippa of Nettesheim and Paracelsus, reveal how architectural image-makers used etching’s mercurial, shapeshifting forms and the protean materiality of ornament not only to picture but also to activate alchemical theories and principles of empirical investigation. Dietterlin’s Architectura prints channelled etching’s alchemical dimensions, comparing the material and chemical transformations involved in architectural etching with the processes of transmutation studied in contemporary alchemical research. As is evident from the alchemical imagery that Dietterlin’s Architectura contributed to the court art of Holy Roman Emperor Rudolf II, the Architectura established architectural images as contexts of alchemical thinking in the years around 1600. In sum, the transformative structures of Dietterlin’s architectural etchings allowed architectural prints to become fora for natural philosophical inquiry.