Crown Glass

Crown glass was a type of window glass that was popular in the 1800s.
Glass was blown into a “crown,” or hollow globe, during this process.
This was then transferred from the blowpipe to a punty and flattened by reheating and centrifugally spinning out the bowl-shaped piece of glass into a flat disc up to 5 or 6 feet in diameter.

Uses for Crown Glass

It was commonly used for doors, sidelights, windows, and cabinetry, and was also known as bullseye glass.
It can also be used to glaze entire openings and partitions, adding period-appropriate elegance and daylight while obscuring views and providing privacy.

Crown Glass Manufacturing Process

The process starts with a ball of semi-molten glass on the end of a blowpipe, which is gradually blown and opened outwards like a “crown.”
It is then transferred from the blowpipe to a pontil, or “punty” iron rod, which is opened and flattened by reheating and rapidly spinning it.
The disc’s outer edges are trimmed, and the remaining ornamental bullseye centre is used to decorate windows, doors and sidelights.

History of Crown Glass

The French perfected the process of making crown glass window panes in the 1320s, and its production method remained a closely guarded trade secret until 1678, when it began to be produced in London.
It remained a popular method of glass production until the nineteenth century.