Transparency and luminescence have reemerged 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. Recent 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.