For the everyday education of students in schools, objects are made available to teachers that illustrate subject matter and make it comprehensible. These objects are created to make something visible, so that it can be presented, worked on, and understood. This article starts from the assumption that didactic objects are not neutral media: In the course of their manufacturing, educational theory as well as everyday knowledge about the 'nature' and particularity of students, teachers, and classroom lessons are technically inscribed into them. This article explicates work with didactic objects empirically and shows how this inscription of theoretical perspectives takes place in companies within the education sector. It becomes apparent how specifically designed objects retroact performatively within classroom lessons on those who use them to display and work on school knowledge.