Reference Library: Stained glass
The term 'stained glass' generally refers to glass that has either been painted and fired or colored by adding metallic salts during its manufacture and often both. The latter process is exemplified by, for example, the use of copper to produce green or blue glass or gold oxides to produce reds and oranges.
Stained glass is an art and a craft that requires the artistic skill to conceive the design, and the engineering skills necessary to assemble the piece so that it is capable of supporting its own weight and surviving the elements.
The process used in the 12th century (described below) has changed remarkably little even in modern times:
The molten glass was annealed in a furnace to produce sheets of coloured glass. This so-called 'pot-metal' glass was sometimes rather dark and, to overcome this, 'flashed glass' was made by dipping a lump of white glass on a blowpipe into a pot of red glass and then blowing. This provided sheets of glas with the thin layer of colour. This could then be made bicoloured by grinding off some parts of the colour. The coloured glass was cut into different shapes with a 'grozing iron' and laid out on a table over the original design so that details of the drawing could be seen through it and painted with the oxide pigment on the surface. The pieces were then fired in a kiln.
The oxides permanently fused with the glass to produce the painting, this is the derivation of the term "stained glass". The pieces were then re-assembled with strips of shaped lead, the glass being slotted into the grooves on each side. The pieces were then soldered together, and an oily cement rubbed into the joints to make them watertight, and installed in a frame to create a window.
Copper foil is now sometimes used instead of lead. For further technical details, see Lead came and copper foil glasswork.
Modern coloured glasses are available in varied textures—smooth, wavy, rippled, hammered, pebbled, or very rough. Stained glass is sold by weight and by square foot in sheets, usually about 3' x 4'.
Although described as 'windows' the purpose of stained glass is not to allow those within a building to see out or even to primarily to admit light but rather to control it. As such stained glass windows have been described as 'illuminated wall decorations'. The glass provides visual clues to the purpose of the building and, in a church, tells the Christian story.
Begun in Eastern Asia and among Muslim designers, the art of stained glass reached its height in the Middle Ages. Integrated with the lofty verticals of Gothic cathedrals and parish churches, large windows afforded greater illumination. As windows became larger during the Perpendicular period so glass designs could become more daring. In particular, huge round windows, exemplified by that at Chartres cathedral, called rose windows allowed complicated designs.
At the Reformation, in England large numbers of these windows were smashed and replaced with plain glass. The injunctions of Henry VIII against 'abused images'(the object of veneration) resulted in the loss of thousands of windows. Few remain undamaged; of them the windows in the private chapel at Hengrave Hall in Suffolk are among the finest. With this wave of destruction the art of glass painting died and was not to be rediscovered until the nineteenth century.
With the Catholic revival in England, with its renewed interest in the mediaeval church, there was a revival in the making of stained glass. Artists known for their paintings such as the Pre-Raphaelites William Morris (1834-1898) and Edward Burne-Jones (1833-1898)were among the foremost designers but stained glass making was on an industrial scale. Firms such as Hardmans of Birmingham and Clayton and Bell of London employed artists who were never known outside their particular trade but who filled English churches with their glass. Hardmans did much work for other designers, though William Morris had his own works. Initially Hardmans used A.W.N. Pugin for their design work, mostly on buildings which he had designed, but on his death in 1852, his nephew J. Hardman Powell (1828-1895) took over. A keen Catholic, Powell's work appealed to Anglo-Catholic tastes but he also had a commercial eye and exhibited his works at the Philadephia Exhibition of 1873.
After that the firm did a good deal of work in the United States of America. Clayton and Bell's output was considerable and it was said that most English churches had one of their windows and many had nothing else. Among their designers was Charles Eamer Kempe (1837 - 1907) who set up his own workshop in 1869. His designs were lighter than that of his former employers: it was he who designed all the windows for the chapel of Selwyn College, Cambridge. He is credited with having produced over 3,000 windows. His cousin Walter Tower took over the business - adding a Tower to the Wheatsheaf emblem used by Kempe - and which continued until 1934.
Another important firm was Ward and Hughes which, though it had begun by following the Gothic style changed direction in the 1870s towards a style influenced by the Aesthetic Movement. The firm remained operational until the late 1920s. Yet another was Wiliam Wailes (1808-1881) whose firm produced the West window of Gloucester cathedral. Wailes himself was a business man not a designer but used designers such as Joseph Baguley (1834-1915) who eventually set up his own firm.
Notable American practitioners were John La Farge (1835-1910) and Louis Comfort Tiffany (1848-1933). As to which of them invented the copper-foil alternative to lead is a matter of dispute, but Tiffany is universally credited with developing an opalescent coloured glass and with making extensive use of copper-foil in windows, lamps, and other decorations.
Many of these firms failed in the twentieth century. Much of the work had become merely washed out and colourless; the Gothic movement had been superseded by newer styles. A revival occurred because of the desire to restore the thousands of church windows throughout Europe, destroyed as a result of bombing during the World War II. German artists led the way; notable artists include Ervin Bossanyi, Ludwig Schaffrath, Johannes Shreiter and many others who transformed an ancient art form into a contemporary art form. Thus while there is a deal of often mundane representational work, much of it not made by its designers but industrially produced, there have been notable examples of symmbolic work of which the west windows of Manchester cathedral in England by Tony Hollaway are some of the finest.
Today there are a few academic establishments that teach the traditional skills. One of those establishments is Florida State University's Master Craftsman Program who recently completed the world's largest secular stained-glass windows installed in Bobby Bowden Field at Doak Campbell Stadium. More info at [http://www.craft.fsu.edu Master Craftsman Program]
This article is licensed under the GNU Free Documentation License. It uses material from the Wikipedia article "Stained glass".