The essays in this volume address the problem of three dimensions in architecture and the ways architects in the 16th century (and before and after) solved this problem during the design process. Two-dimensional drawings were used as the most helpful element in the design process, as well as for the presentation of designs. Those involved, not only patrons but also construction workers, should be able to understand what a two-dimensional design would turn out to result in three dimensions. Both drawings in two dimensions and three-dimensional models are well-known tools to architects, but the way in which they employed them together is not always clear. Sometimes architects limited themselves to the making of models only when they believed that these would suffice to communicate the design to others. In other instances, drawings and models were used jointly. Topics of study in this volume include examples of these practices in the work of the Sangallo, Raphael, Vasari, and others.