This title charts new developments in 3D printing and analyses their relevance for the discourse of Architecture. It includes a series of articles by key designers working in this new field, offering an overview of these often extraordinary designs, outlining not only the technical challenges behind the process, but also the often highly sophisticated research behind the designs themselves, based on newly developed strategies, such as biomimetics and other design logics. In addition, it also includes a series of theoretical essays that seek to tease out the relevance of this work for the broader discourse of architecture. Are these designs merely a distraction from the true business of the architect? Or do they point towards a new form of proto architecture - like furniture, espresso makers and pavilions before them - that test out architectural ideas and explore tectonic properties at the scale of the human body? And do they reveal a new form of design exploration that effectively expands the realm of the architect? In short, are these 3D printed items that take the scale of the human body to be seen as a new genre of body architecture? These articles, then, seek to lift this domain beyond a merely technical horizon, in order to rethink the deep implications of these new developments. The volume therefore contains a range of perspectives. What unites the whole volume, however, is that all the contributors have been trained as architects.