Whoever designs attempts to give form to the unknown. He or she builds a bridge into the void through graphic representations and models. In modern terminology, "designing" encompasses nearly all practices involved when images, architectures, or machines are conceived. The contributions in this volume address the history and theory of these paper and model adventures and examine the modes of designing action, that is, the procedures developed in the use of tools and models. In doing so, the portraits of design tools gathered here explore the exteriority of shaping, forming, and thinking both thematically and methodologically: on one hand, in relation to the concept of the tool, which is subjected to critical revision; on the other hand, in relation to the concept of designing as a practice.