With the aim of contributing to the scholarship on costume designers’ agential collaboration within contemporary dance, this article centres on the creative authorship of the designer. Using the notions of ‘signature style’ and ‘authorship’ as the key research lenses, it investigates the work of Finnish costume designer Erika Turunen within contemporary dance, specifically her collaboration with choreographer Tero Saarinen. Drawing from in-person interviews with the designer and materials related to her costumes, this article addresses the issues of re-invention versus repetition, and process and outcome as two interlinked steps in the creation of Turunen’s signature style.