Historical Traditions in the Manufacture of Antique Window Glass

History of Antique Window Glass

Ancient Beginnings

The history of antique window glass goes back to a time just before the turn of the first century AD. Phoenicians along the Syrian-Palestinian coast developed a technique of glassblowing that allowed for a variety of shapes of hollow glass items. Spreading throughout Germany, Italy, France, and Switzerland as a result of the rise of the Roman Empire, glassmaking flourished and the Romans began using it for architectural purposes.

Antique Window Glass: Then and Now

It wasn't until the 11th century that the mouth-blown cylinder technique of making sheet glass for windows was first developed in Germany and later adopted by the Venetians. Cylinder Glass and Crown Glass are two types of authentic, mouth-blown antique window glass typically found in historical structures in the United States. Both types employ a blowpipe to shape the molten glass.

Cylinder glass begins as a ball of molten glass on the end of a blowpipe that is rhythmically blown and swung in a deep pit until an elongated pod-shape forms and a desired length and diameter are reached. The ends of the "pod" are cut from the glass to form a cylinder, which is then cooled, scored down its length, reheated, and flattened.

Crown glass was originally developed in the 7th - 8th century and later revived for the purpose of window glass making as an alternative to the mouth-blown cylinder glass. The process for blowing Crown glass, also called bullion because of its disc-like shape, is slightly different. It begins with a ball of semi-molten glass on the end of a blowpipe that is opened outwards on the opposite side of the pipe like a "crown." It is then transferred from the blowpipe to a pontil, or "punty" iron rod, and flattened into a bullion or disc-shape by reheating and spinning. The outer parts of the disc were used for window panes. Due to the size limitations of this glass, oftentimes panes had to be joined together with lead strips to create windows. The bullseye centers became decorative elements for doors, windows, and furniture.

Although replaced by modern methods developed during the Industrial Revolution, some of these early manufacturing processes for making window glass are still practiced in Europe today, capturing the original look and feel of authentic antique window glass. Glashütte Lamberts of Germany is generally acknowledged to be producer of the finest mouth-blown glass in the world. Our collaboration brings you a selection of restoration window glass types for the building and restoration of fine American buildings, homes, and furniture spanning the 17th - early 20th centuries:

Mouth Blown Cylinders
(Bendheim Light Restoration Glass®)

Manufacture of Antique Window Glass After the Industrial Revolution

The Industrial Revolution of Western Europe eventually made its way across the ocean to influence the industrialization of the United States and many of its manufacturing processes. Window glass found in many American homes and structures after the beginning of the 20th century was no longer produced by the mouth-blown method.

In 1903 the first mechanical method for "drawing" cylinders of window glass was invented in the United States. Somewhat resembling the mouth-blown process for making cylinder glass, large cylinders of glass measuring forty feet in height were drawn vertically from a circular tank and then cut into seven to ten foot cylinders. Just as with the mouth-blown method, the drawn cylinder glass was cut lengthwise, reheated and flattened.

Bendheim Restoration Glass®: All the Beauty of Authentic Antique Window Glass Today

Now you can have the old world look and feel you desire, including the characteristic imperfections found in authentic antique window glass, in a special glass product that offers you:

Antique glass look and feel made using the authentic mouth-blown cylinder and crown glass techniques as they have been preserved and handed down through generations of Lamberts craftsmen
Custom sizes cut to your specification
Greater ease of handling than salvaged antique glass from old windows
Consistency of brilliance and body
Available in safety laminated form to meet stringent modern building safety codes and provide sound control benefits

Bendheim Restoration Glass® — the mark of distinction.