Building prototypes and models is an essential component of any design activity. Modern product development is a multi-disciplinary effort that relies on prototyping in order to explore new ideas and test them sufficiently before they become actual products. A comprehensive modern prototyping approach is crucial to making informed design decisions, and forms a strategic part of a successful designer’s toolkit. Bjarki Hallgrimsson is a practicing product development consultant and an Associate Professor at the School of Industrial Design, Carleton University, Ottawa.