The dramatic growth and popularization of the early 20th century Art Deco, Streamline, and Moderne architectural styles were fueled, in part, by technological advances in the building materials industry. New products, such as stainless steel and plastics, enlarged the realm of architectural design. The more traditional materials, on the other hand, quickly developed fresh, innovative forms and uses. For example, the architectural glass industry became especially creative, introducing a series of new glass products known as structural glass. Used predominately for wall surfacing, these now familiar products included glass building blocks, reinforced plate glass, and pigmented structural glass. Pigmented structural glass, popularly known under such trade names as Carrara Glass, Sani Onyx (or Rox), and Vitrolite, revolutionized the business and rapidly became a favorite building material of the period's architects and designers.

The Club Moderne, Anaconda, Montana, reflects the exceptional historic detailing associated with pigmented structural glass--polished-mirror finish, rounded corners, and horizontal polychorme bands. Photo: Jet Lowe, HAER collection, NPS.

The versatility of pigmented structural glass contributed to its popularity. Not only could the material be applied to both the exterior and interior, the glass could he sculptured, cut, laminated, curved, colored, textured, and illuminated. Often applied directly over existing architecture to remodel older buildings, as well as in new construction, a veneer of pigmented structural glass had the ability to define a building's architectural character as new and up-to-date. Pigmented structural glass also complemented the period's silvery metal accents and affinity for slick, shiny surfaces. A successful application of a structural glass veneer often resulted in a streamlined look characteristic of the Art Moderne architectural style.

As tastes changed and production costs rose, however, pigmented structural glass fell into disfavor and disuse by mid-20th century. With today's rekindled interest in the Art Deco, Art Moderne, and Streamline styles, the preservation and replacement of pigmented structural glass have now become an integral part of many rehabilitation projects, particularly in relation to commercial storefronts. This brief, then, was developed in order to address some of the major deterioration problems associated with pigmented structural glass and to recommend methods for maintaining, repairing, and, if necessary, replacing damaged or missing pieces of pigmented structural glass.