This research report discusses and reflects on the development of the costume design and choreography of the performance piece Cuttlefish, 2017–19. In the performance, the costumes played an essential role as they completely transformed the movements and forms of the dancers. To enable this, costumes were designed as temporal forms, garments that contain a particular movement language based on the structural possibilities of the body. The costumes are discussed here from two perspectives: in relation to their role in constructing a narrative for the audience, choreographer and dancers and secondly concerning the practical aspects of their development as temporal forms. The suggestion is that garments constitute material opportunities, designed to provide a system of possible movements and expressions that the choreographer and dancer can explore. The result has implications for both fields of fashion design and costume design as it proposes fundamental parameters for a method of constructing garment as temporal form.