Digital fabrication and "3D Making" are prominent recent additions to school curricula, hastened by the increased affordability of Computer Assisted Design software and devices such as 3D printers. It is increasingly argued that classroom use of these technologies can re-orientate schools towards forms of skills and knowledge appropriate for contemporary industry, STEM education and "Maker culture". Amidst such rhetoric, questions are raised about how these technologies are being used in schools, and the extent to which this represents "new" and/or "innovative" forms of education. This paper presents an ethnographic investigation of a 3D printing course enacted in an Australian high school. These curricular activities are considered from three different perspectives: (i) the artefacts and devices involved in the project; (ii) the surrounding social and educational contexts; and (iii) the activities and practices implicit in the implementation of the project. These different levels of analysis highlight the complexities of technology-based schooling--not least the ways in which possible technical and/or pedagogical "innovations" associated with 3D printing are shaped by the situational constraints of school contexts. The paper concludes by considering the likely future(s) of 3D printing and other forms of digital fabrication within the institutional confines of school.