Transparency and luminescence have re-emerged in the vocabulary of architecture, and light and "lightness" have become key concepts for a significant number of contemporary architects, as well as artists who create installations. Work by these designers recalls the use of transparent materials in early modern structures, but they have introduced new ideas and technical solutions. In doing so, they have redefined the relationship between the observer and the structure by interposing elements that both veil and illuminate. In this architecture of lightness, buildings become intangible, structures shed their weight and facades become unstable, dissolving into an often luminous evanescence. The 33 projects illustrated in this book exemplify this emerging sensibility, which is examined in an essay by Terence Riley that places the new work in a broad historic and cultural perspective. More than 30 architects are represented in this international selection, which includes a broad range of building types, scales and technologies. Among these architects are: Renzo Piano, Herzog & de Meuron, Jean Nouvel, Toyo Ito, Tod Williams and Billie Tsien.