Integral to architectural practice and theory are techniques for the representation of form: not just the forms of building structures, but also the networks of utilities that make them habitable, the natural, biological, and social processes they engender or inhibit, and the interaction of all of these with their exterior environment and interior space. The techniques used have their own subtle histories and conventions, based and constrained both in the abstract prevailing ideas about what is and is not important to represent, and in the material technologies available to do so. In A Catalog of Difference, Andrew Lucia seeks to challenge and unseat, or at least unsettle, the comfort with which practitioners of design make these assumptions. Its three series of studies of increasing complexity progressively apply new techniques for the representation of ambient light and geometrical surfaces.