Structural Pigmented Glass Part 1

By Rosemary Thornton

Structural pigmented glass -- better known by its trade names of Vitrolite, Sani Onyx and Carrara -- helped define "modern" architecture and interior design from the 1920s to the 1940s. Glittering movie palaces, streamlined downtown storefronts, public restrooms, even modest residential kitchens were covered with the sleek, glass tile. It was the perfect marriage of new technology to human imagination.

Structural glass was touted as a non-porous, ultra-modern building material that was as durable as marble, but cheaper and easier to install. One of its best qualities, according to advertisements of the age, was that it was swank, but so swishable. Vitrolite manufacturer Libbey-Owens-Ford based in Rossford, Ohio claimed the stroke of a damp cloth will keep it spotless.

Many people dont know this unique building material by name but recognize it by sight. Youve probably seen sheets of it on "Popcorn Palaces" grand old Art Deco or Art Moderne theatres in downtown districts. Or you might have noticed the colorful and highly-polished tiled wainscoting in the bathrooms and kitchens of upper-scale 1930s homes.

In 1900, the Marietta Manufacturing Company claimed to be the first producer of pigmented structural glass, rolling the first sheet of Sani Onyx (Rox). Penn-American Plate Glass Company began manufacturing white and black Carrara Glass around 1906, no doubt selected the name "Carrara" for the close resemblance of the white glass to the white marble from the Carrara quarries of Italy. Shortly after, Libby-Owens-Ford Glass began production of their own version of structural glass, Vitrolite.

In the early 1900s, this new building material was heralded as the last word in sanitation and cleanliness. At first, it was recommended for use in hospitals, doctors offices and laboratories because it could not be damaged by acids or harsh chemicals. It soon became a popular material for countertops in confectionaries, bars, bakeries and butcher shops because it was durable and easy to clean.

The Woolworth Building, built in 1913, saw the first large-scale interior use of pigmented structural glass in its restrooms; the walls were covered with sheets of the glass.

In the early years, structural glass was offered only in black and white. Then advances in manufacturing techniques of structural glass caught the fancy of architects and designers. Structural glass could now be pigmented and etched with patterns or decorated with inlaid designs. As a Preservation Brief issued by the Department of Interior states, the glass could be sculptured, cut, laminated, curved, colored, textured, and illuminated.

Its versatility and availability in vivid colors such as orchid, fire engine red, burgundy and maroon made it a natural for theaters and restaurants built or renovated during the Art Deco period the 1920s and 30s.

In October 1935, American Builder Magazine promoted and announced the prizewinners for a Modernize Main Street Competition, with $11,000 in cash prizes awarded to 52 architects. The contest was sponsored by Libbey-Owens-Ford Glass Company, makers of Vitrolite. Architects were asked to provide designs that demonstrated simplicity, economy, unbroken horizontal lines, pure colors and functionality.

The architects drawings present splendid solutions to one of the building industrys most urgent problems namely, what to do to the old style stores and shops, that stand on every business street, blocking progress and losing trade because of their uninviting appearance (American Builder, October 1935, p. 66).

Of course, the prize-winning splendid solutions called for the installation of Vitrolite.

Structural glass also became a popular building material in modern homes. In the 1920s, a growing understanding of the germ theory made glass very appealing to harried housewives who worked tirelessly to keep the home sparkling. Sanitary and easy to clean were the watchwords of the era, especially when it came to kitchens and baths; now known to be harbingers of dirt and disease.

By 1940, the whirlwind love affair with the bold, shiny colors and elegant curves of structural glass was all but over. Rising production costs combined with capricious popular tastes, and structural glass fell from favor. After World War II, other building materials replaced Vitrolite in both new construction and remodeling.

Production of structured glass ceased in this country in 1947, making preservation of existing pieces urgent, and restoration somewhat difficult. Preservationists generally recommend that the original structural glass be repaired if at all possible, since there are no true modern replacements for the heavy pigmented structural glass of the 1920s-40s.

One European manufacturer makes a thinner version of Vitrolite, known as Vitrolux or Spandrelite. This heavy plate glass has a colored ceramic surface fired to the back of the glass. Examples of it can be found in the black or bronzed glass panels of modern office buildings.

And theres always salvage. One man in St. Louis who collects Vitrolite and has a little extra structural glass safely stowed in the basement of his shop. Like about ten tons of it. Not only does he broker structural glass to clients all over the world, but Timothy Dunn is also the countrys foremost authority on the repair and restoration of Vitrolite. Dunn is, in his own words, "The Oman of Vitrolite."

>> To Part II, "The Oman of Vitrolite"

More information:

Preservation Brief 12 Preservation of Historic Pigmented Structural Glass (Vitrolite and Carrara Glass)

The Vitrolite Specialist Web site