stained glass - Manufacture, History

Pieces of different coloured glass mounted in lead framing to form a pictorial image or pattern. It was introduced from Byzantine art for the windows of European buildings in the late 12th-c, and flourished most splendidly in Western Romanesque and Gothic churches. It remained popular throughout the mediaeval period, and was enthusiastically revived in the 19th-c (eg by Burne-Jones, Matisse, Rouault) and later in the USA by Louis Comfort Tiffany (1848–1933). In the Middle Ages the glass itself was often coloured by the addition of metal oxides during the glass-making process, or by the layering of coloured glass over uncoloured glass (flashing); but from the 16th-c the technique of painting in enamel on the glass became more common.

The term stained glass refers either to the material of coloured glass or to the art and craft of working with it.

As a material the term generally refers to glass that has been coloured by adding metallic salts during its manufacture.

Stained glass, as an art and a craft, requires the artistic skill to conceive the design, and the engineering skills necessary to assemble the decorative piece, traditionally a window, so that it is capable of supporting its own weight and surviving the elements.

Although usually described as stained glass windows the purpose of stained glass is not to allow those within a building to see out or even primarily to admit light but rather to control it.

Manufacture

Glass production

From the 10th or 11th century, when stained glass began to flourish as an art, glass factories were set up where there was a ready supply of silica, the essential product of glass manufacture. Glass was usually coloured by adding metallic oxides to the glass while in a molten state in a clay pot over a furnace.

Cylinder glass This glass was then collected from the pot into a molten globule and blown, being continually manipulated until it formed a large cylindrical bottle shape of even diameter and wall-thickness. This is the type of glass most commonly used for ancient stained glass windows.

Crown glass This glass was partly blown into a hollow vessel, then put onto a revolving table which could be rapidly spun like a potter's wheel. This glass could be made coloured and used for stained glass windows, but is typically associated with small paned windows of 16th and 17th century houses.

Table glass This glass was produced by tipping the molten glass onto a metal table and sometimes rolling it. The glass thus produced was heavily textured by the reaction of the glass with the cold metal. Glass of this appearance is commercially produced and widely used today, under the name of cathedral glass, although it was not the type of glass favoured for stained glass in ancient cathedrals.

Flashed glass Red pot metal glass was often undesirably dark in colour and prohibitively expensive. In this procedure, a semi-molten cylinder of colourless glass was dipped into a pot of red glass so that the red glass formed a thin coating. The other advantage was that the red of double-layered glass could be engraved or abraded to show colourless glass underneath. Some stained glass studios, notably Lavers and Barraud, made extensive use of large segments of irregularly flashed glass in robes and draperies.

There still exist a number of glass factories, notably in Germany, USA, England, France, Poland and Russia which continue to produce high quality glass by traditional methods primarily for the restoration of ancient windows. Modern stained glass windows often use machine made glass, slab glass, which as its name suggests is very thick, and so-called cathedral glass which is sometimes heavily textured.

Creating stained glass windows

The first stage in the production of a window was to make, or acquire from the architect or owners of the building, an accurate template of the window opening that the glass was to fit. Details of faces, hair and hands were painted onto the inner surface of the glass in a special glass paint which contained finely ground lead or copper filings, ground glass, gum arabic and a medium such as wine, vinegar or urine. The joints were then all soldered together and the glass pieces were stopped from rattling and the window made weatherproof by forcing a soft oily cement or mastic between the glass and the cames. In the 1500s a range of glass stains were introduced, most of them coloured by ground glass particles. By the 1600s a style of stained glass had evolved that was no longer dependent upon the skilful cutting of coloured glass into sections.

Technical details

Large Late 12thC window with recently-restored Early 13thC glass showing details of metal supporting frame

Detail, 13thC, showing St Thomas a Becket

Showing the pot metal and painted glass, lead H-sectioned cames, modern steel rods and copper wire attachments

European panel, 1564, with typical painted details, extensive silver stain, Cousin's rose on the face and flashed ruby glass with abraded white motif

History

Origins

Coloured glass has been produced since ancient times.

In Early Christian churches of the 4th and 5th centuries there are many remaining windows which are filled with ornate patterns of thinly-sliced alabaster set into wooden frames, giving a stained-glass like effect.

A perfume flask from 100BCE-200CE

The Portland Vase, a rare example of Roman flashed glass

Alabaster window from St Peter's Basilica, Rome, 16th century

Stained glass in the Nasir ol Molk mosque in Iran

Medieval glass

Stained glass, as an art form, reached its height in the Middle Ages. In the Romanesque and Early Gothic period, from about 950 CE to 1240 CE, the untraceried windows demanded large expanses of glass which of necessity were supported by robust iron frames, such as may be seen at Chartres Cathedral and at the Eastern end of Canterbury Cathedral.

Integrated with the lofty verticals of Gothic cathedrals and parish churches, the glass designs became more daring. The circular form, or rose window developed in France from relatively simple windows with pierced openings through slabs of thin stone to wheel windows, as exemplified by that in the West front of Chartres cathedral, and ultimately to designs of enormous complexity, the tracery being drafted from hundreds of different points, such as those at St. Chapelle, Paris and the Bishop's Eye, Lincoln.

Windows from Chartres, C13th.

West window of Lincoln

The Rose window from Saint Chapelle, C15th.

Destruction and continuation

At the Reformation, in England large numbers of these windows were smashed and replaced with plain glass.

In Europe, however, stained glass continued to be produced in the Classical style widely represented in Germany, despite the rise of Protestantism, in Belgium, in France, particularly at the Limoges factory, and at Murano in Italy where stained glass and faceted lead crystal are sometimes in evidence in the same window.

Post Reformation window in Speyer, Germany

Les Andelys, Normandy, 16th century

Ghent Cathedral, Belgium, 16th century

Cologne Cathedral, window using painterly technique

Revival

The Catholic revival in England, gaining force in the early 19th century, with its renewed interest in the mediaeval church brought a revival of church building in the Gothic style, claimed by John Ruskin to be "the true Catholic style". This section is expanded at Stained glass - British glass, 1811-1918.

Hardman of Birmingham

Because of the technical requirements, stained glass making was generally on an industrial scale.

Famous manufacturers of the mid 19th century

St. Andrew's, Sydney, Hardman of Birmingham, 1861-67, typical in its elegance, the skilful arrangement of figures and the narrational quality.

William Morris

Among the foremost designers were the Pre-Raphaelites, William Morris (1834-1898) and Edward Burne-Jones (1833-1898). As part of Morris's enterprise, he set up his own glass works, producing glass to his own and Burne-Jones designs.

Clayton and Bell, and Kempe

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.

Heaton, Butler and Bayne window, showing this firm's liking for tertiary colours, large areas of flashed glass and solid, naturalistic figures.

Burlison and Grylls window.

Ward and Hughes, William Wailes

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.

Tiffany and La Farge

Notable American practitioners include John La Farge (1835-1910) who invented opalescent glass and for which he received a US patent February 24, 1880, and Louis Comfort Tiffany (1848-1933), who received several patents for variations of the same opalescent process in November of the same year and is believed to have invented the copper foil method as an alternative to lead, and used it extensively in windows, lamps and other decorations.

Window by Tiffany with distinctive opalescent glass, asymmetric design and casual combination of flashed, painted and pot metal glass within the formal framework of supporting bars	St. Walburge, Lorraine designer Gabriel Loire, mid 20thC, combines traditional pot metal and leading with modern design, achieving an overall appearance that acknowledges the Medieval origins.	The Good Shepherd window at Port Sunlight, 1949.	Late 20th century window in the crypt of the Abbey of St Denis, The skilful adaptation of ancient tradition and modern style in a World Heritage site. Thus while there is a deal of often mundane representational work, much of which is not made by its designers but industrially produced, there have been notable examples of symbolic work of which the west windows of Manchester cathedral in England by Tony Hollaway are some of the finest. More info at Master Craftsman Program St Joseph church, Le Havre, Normandie Buckfast Abbey, Devon, England. Franciscan Church, Kraków, designer Stanisław Wyspiański Secular glass, Montreal metro, Canada, by Marcelle Ferron Buildings incorporating stained glass windows Churches and Cathedrals Stained glass windows were commonly used in churches for decorative and informative purposes. For more information on the use of stained glass to depict religious subjects, see Poor Man's Bible Churches Cathedrals Chapels Important examples Sainte-Chapelle, in Paris, France Cathedral of Chartres, in Chartres, France Canterbury Cathedral, in England Houses Stained glass windows in houses were particularly popular in Victorian era and many domestic examples survive. See Art glass Beveled glass Cathedral glass Prairie style homes The houses of Frank Lloyd Wright Stained glass lamp / Lampshades Tiffany lamp Public and commercial use of stained glass Town halls and other public buildings often incorporate stained glass or leadlighting.	il Duomo,Florence, an ancient window	Stained glass inside Saint Pierre (Caen)	Arezzo, Italy, a Renaissance window in the untraceried circular shape or ocula favoured in Italy
Dramburg Church, a good example of heraldic glass	St Germain des Pres, Paris, glass in a Renaissance church	Altenberger, a colourless window in the style known as Grisaille with a small heraldic motif	Calke Abbey, Derbyshire, 19th century window
Yale University, the Education window by Tiffany	Ins, Switzerland, modern figurative glass	Abstract stained glass, Beth El Congregation near Washington, DC by David Ascalon	Meiningen Catholic Church, 20th century glass