Stained glass

"For the Blackford Oakes novel, see Stained Glass (novel)"

The term stained glass refers either to the material of coloured glass or to the art and craft of working with it. Throughout its thousand-year history the term "stained glass" was applied almost exclusively to the windows of churches, cathedrals and other significant buildings. Although traditionally made in flat panels and used as windows, the creations of modern stained glass artists also include three-dimensional structures and sculpture.

Modern vernacular usage has often extended the term "stained glass" to include domestic leadlight and objets d'art created from lead came and copper foil glasswork such as exemplified in the famous lamps of Louis Comfort Tiffany.

As a material the term "stained glass" generally refers to glass that has been coloured by adding metallic salts during its manufacture. The coloured glass is crafted into "stained glass windows" in which small pieces of glass are arranged to form patterns or pictures, held together (traditionally) by strips of lead and supported by a rigid frame. Painted details and yellow stain are often used to enhance the design. The term "stained glass" is also applied to windows in which all the colours have been painted onto the glass and then annealed in a furnace.

Stained glass, as an art and a craft, requires the artistic skill to conceive an appropriate workable design, and the engineering skills necessary to assemble the decorative piece, traditionally a window, so that it will fit snugly into the window frame for which it is made and also, especially in the larger windows, is capable of supporting its own weight and surviving the elements. Many large windows have withstood the test of time and remained substantially intact since the late Middle Ages. In Western Europe they constitute the major form of pictorial art to have survived. In this context, the purpose of a stained glass window is not to allow those within a building to see the world outside or even primarily to admit light but rather to control it. For this reason stained glass windows have been described as 'illuminated wall decorations'.

The design of a window may be non-figurative or figurative. It may incorporate narratives drawn from the Bible, history or literature, or represent saints or patrons. It may have symbolic motifs, in particular armorial. Windows within a building may be thematic, for example: within a church - episodes from the life of Christ; within a parliament building - shields of the constituencies; within a college hall - figures representing the arts and sciences; or within a home - flora, fauna or landscape.

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. Glass coloured in this way was known as "pot metal". Copper oxides were added to produce green, cobalt for blue, and gold was added to produce red glass. Much modern red glass is produced using ingredients less expensive than gold and giving a brighter red of a more vermilion shade.

Cylinder glassThis glass was collected from the pot into a molten ball and blown, while being continually manipulated until it formed a large cylindrical bottle shape of even diameter and wall-thickness. It was then cut open, laid flat and annealed to make it stable. This is the type of glass most commonly used for ancient stained glass windows.

Crown glassThis glass was partly blown into a hollow vessel, then put onto a revolving table which could be rapidly spun like a potter's wheel. The centrifugal force caused the molten material to flatten and spread outwards. It could then be cut into small sheets. 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. The concentric, curving ripples are characteristic of this process. The center of each piece of glass received less force during the spinning, and thus produced was a thicker piece. These centres were for the special effect created by their lumpy, refractive quality. They are known as "bull's eyes" and are feature of late 19th century domestic leadlight and are sometimes also used with "cathedral glass" or "quarry glass" in non-pictorial church windows of that date.

Table glassThis glass was produced by pouring molten glass onto a metal table and sometimes rolling it with a large metal cylinder. The glass thus produced is 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. It has been much used for lead lighting in churches in the 20th century. Modern glass made by this technique is often heavily patterned by the use of an engrave metal roller.

Flashed glassRed pot metal glass was often undesirably dark in colour and prohibitively expensive. The method developed to produce red glass was called "flashing". In this procedure, a semi-molten cylinder of clear glass was dipped into a pot of red glass so that the red glass formed a thin coating. The laminated glass thus formed was cut, flattened and heat annealed.

There are a number of advantages to this technique. It allows a variety in the depth of red ranging from very dark and almost opaque, through ruby red to pale and sometimes streaky red that was often used for thin border pieces. The other advantage was that the red of double-layered glass could be engraved or abraded to allow light to shine through the clear glass underneath. In the late Medieval period, this method was often employed to add rich patterns to the robes of Saints. The other advantage, much exploited by late Victorian and early 20th century artists, was that sheets could be flashed in which the depth of colour varied across the sheet. This was applied to a range of colours. Some stained glass studios, notably Lavers, Barraud and Westlake in England, made extensive use of large segments of irregularly flashed glass in robes and draperies.

Modern production of traditional glassThere are a number of glass factories, notably in Germany, USA, England, France, Poland and Russia, which produce high quality glass by traditional methods. Such glass is produced primarily for the restoration of older windows from 1920s and before. The production of new windows in traditional Victorian, Arts and Crafts and early 20th century styles often uses traditional glass. Modern stained glass windows also often use a variety of these different types of glass, or employ commercially made glass.

Creating stained glass windows

* The first stage in the production of a window is to make, or acquire from the architect or owners of the building, an accurate template of the window opening that the glass is to fit.
* The subject matter of the window is determined to suit the location, a particular theme, or the whim of the patron. A small design called a "Vidimus" is prepared which can be shown to the patron.

* A traditional narrative window has panels which relate a story. A figurative window could have rows of saints or dignitaries. Scriptural texts or mottoes are sometimes included and perhaps the names of the patrons or the person as whose memorial the window is dedicated. In a window of a traditional type, it is usually at the discretion of the designer to fill the surrounding areas with borders, floral motifs and canopies.

* A full sized cartoon is drawn for every "light" (opening) of the window. A small church window might typically be of two lights, with some simple "tracery" lights above. A large window might have four or five lights. The east or west window of a large cathedral might have seven lights in three "tiers" with elaborate tracery. In Medieval times the cartoon was drawn straight onto a whitewashed table, which was then used for cutting, painting and assembling the window.

* The designer must take into account the design, the structure of the window, the nature and size of the glass available and his own preferred technique. The cartoon is then be divided into a patchwork as a template for each small glass piece. The exact position of the lead which holds the glass in place is part of the calculated visual effect.

* Each piece of glass is selected for the desired colour and cut to match a section of the template. An exact fit is ensured by "grozing" the edges with a tool which can nibble off small pieces.

* Details of faces, hair and hands can be painted onto the inner surface of the glass in a special glass paint which contains finely ground lead or copper filings, ground glass, gum arabic and a medium such as wine, vinegar or (traditionally) urine. The art of painting details became increasingly elaborate and reached its height in the early 20th century.

* Once the window is cut and painted, the pieces are assembled by slotting them into H-sectioned lead "cames". The joints are then all soldered together and the glass pieces are stopped from rattling and the window made weatherproof by forcing a soft oily cement or "mastic" between the glass and the cames.

* Traditionally, when the windows were inserted into the window spaces, iron rods were put across at various points, to support the weight of the window, which was tied to the rods by copper wire. Some very large early Gothic windows are divided into sections by heavy metal frames called "ferramenta". This method of support was also favoured for large, usually painted, windows of the Baroque period.

* From 1300 onwards, artists started using "silver stain" which was made with silver nitrate. It gave a yellow effect ranging from pale lemon to deep orange. It was usually painted onto the outside of a piece of glass, then fired to make it permanent. This yellow was particularly useful for enhancing borders, canopies and haloes, and turning blue glass into green glass for green grass.

* By about 1450 a stain known as "Cousin's rose" was used to enhance flesh tones.

* In the 1500s a range of glass stains were introduced, most of them coloured by ground glass particles. They were a form of enamel. Painting on glass with these stains was initially used for small heraldic designs and other details. By the 1600s a style of stained glass had evolved that was no longer dependent upon the skilful cutting of coloured glass into sections. Scenes were painted onto glass panels of square format, like tiles. The colours were annealed to the glass and the pieces were assembled into metal frames.

* In modern windows, copper foil is now sometimes used instead of lead. For further technical details, see Lead came and copper foil glasswork.

Technical details

History

Origins

Coloured glass has been produced since ancient times. Both the Egyptians and the Romans excelled at the manufacture of small coloured glass objects. The British Museum holds two of the finest Roman pieces, the Lycurgus Cup, which is a murky mustard colour but glows purple-red to transmitted light, and the Portland vase which is midnight blue, with a carved white overlay.

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. Similar effects were achieved with greater elaboration using coloured glass rather than stone by Muslim architects in Southwest Asia. In the 8th century, the Muslim alchemist Jabir ibn Hayyan (Geber) scientifically described 46 original recipes for producing coloured glass in "Kitab al-Durra al-Maknuna" ("The Book of the Hidden Pearl"), in addition to which 12 recipes were inserted by al-Marrakishi in a later edition of the book. Jabir also described the production of high quality coloured glass cut into artificial gemstones. [Ahmad Y Hassan, [http://www.history-science-technology.com/Articles/articles%209.htm The Manufacture of Coloured Glass] and [http://www.history-science-technology.com/Articles/articles%2093.htm Assessment of "Kitab al-Durra al-Maknuna"] , "History of Science and Technology in Islam".]

Medieval glass

Stained glass, as an art form, reached its height in the Middle Ages when it became a major pictorial form and was used to illustrate the narratives of the Bible to a largely illiterate populace.

In the Romanesque and Early Gothic period, from about 950 AD to 1240 AD, 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. As Gothic architecture developed into a more ornate form, windows grew larger, affording greater illumination to the interiors, but were divided into sections by vertical shafts and tracery of stone. The elaboration of form reached its height of complexity in the Flamboyant style in Europe and windows grew still larger with the development of the Perpendicular style in England.

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 Sainte-Chapelle, Paris and the "Bishop's Eye" at Lincoln Cathedral.

Destruction and continuation

At the Reformation, in England large numbers of these windows were smashed and replaced with plain glass. The Dissolution of the Monasteries under Henry VIII and the injunctions of Oliver Cromwell 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 the latter wave of destruction the traditional methods of working with stained glass died and were not to be rediscovered in England until the early 19th century. For more details

In Europe, however, stained glass continued to be produced in the Classical style which is widely represented in Germany, Belgium and Holland, despite the rise of Protestantism. In France much glass of this period was produced at the Limoges factory, and at Murano in Italy, where stained glass and faceted lead crystal are often coupled together in the same window.Ultimately, in France the French Revolution brought about the neglect or destruction of many windows.

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". The architectural movement was led by Augustus Welby Pugin. Many new churches were planted in large towns and many old churches were restored. This brought about a great demand for the revival of the art of stained glass window making.

Hardman of Birmingham

Because of the technical requirements, stained glass making was generally on an industrial scale. Firms such as Hardman & Co. 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. Initially most of Hardman's designs were by A.W.N. Pugin and were installed in buildings of which he was the architect, but on his death in 1852, his nephew John 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 Philadelphia Exhibition of 1873. After that the firm did a good deal of work in the United States of America.

Famous manufacturers of the mid-19th centuryWilliam MorrisAmong the foremost designers were the Pre-Raphaelites, William Morris (1834-1898) and Edward Burne-Jones (1833-1898). While Burne-Jones is best known today as a painter, William Morris's studios created designs for architectural and interior decorating of many sorts including paintings, furniture, tiles and textiles. As part of Morris's enterprise, he set up his own glass works, producing glass to his own and Burne-Jones's 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. 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.

Gallery of 19th and early 20th century windows, displaying four very different styles.

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. The firm remained operational until the late 1920s. Yet another was William 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.

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.

Twentieth century

Many 19th century firms failed early in the twentieth century as 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. Much work of the period is mundane and often is not made by its designers but industrially produced. However, there are many artists who have transformed an ancient art form into a contemporary art form, sometimes using only traditional techniques but often exploring the medium of glass in different ways and in combination with different materials. The use of slab glass set in concrete has been another 20th century innovation. "Gemmail" glass, developed in 1936, by the French artist Jean Crotti, is a type of stained glass where the pieces of glass that are adjacent to each other overlap allowing for a greater diversity and subtlety of colour. [ [http://www.gemmail.com/en/rmn/ENRMN.htm Gemmail, Roger Malherbe] ]

Today there are academic establishments that teach the traditional skills. One of these 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.

In the US, there is a 100-year-old trade organization, The Stained Glass Association of America, whose purpose is to function as a publicly recognized organization to assure survival of the craft by offering guidelines, instruction and training to craftspersons. The SGAA also sees its role as defending and protecting its craft against regulations that might restrict its freedom as an architectural art form. The current president is B. Gunar Gruenke of the Conrad Schmitt Studios.

Notable stained glass artists of the period include Ervin Bossanyi, Patrick Reyntiens, Ludwig Schaffrath, Johannes Shreiter, Douglas Strachan, Judith Schaechter, Jean René Bazaine at Saint Séverin and the Loire Studio of Gabriel Loire at Chartres. Luxus Keibel studio in Mexico specialises in domestic stained glass in both contemporary and 19th century styles. The west windows of Manchester cathedral in England by Tony Hollaway are some of the most notable examples of symbolic work.

Buildings incorporating stained glass windows

Churches and Cathedrals

Stained glass windows were commonly used in churches for decorative and informative purposes. Many windows are donated to churches by members of the congregation as memorials of loved ones. For more information on the use of stained glass to depict religious subjects, see Poor Man's Bible
* Churches
* Cathedrals
* Chapels

* Important examples
**Cathedral of Chartres, in France- 11th-13th century glass
**Canterbury Cathedral, in England- 12th-15th century plus 19th-20th century glass
**York Minster, in England- 11th-15th century glass
**Sainte-Chapelle, in Paris, 13th-14th century glass
**Florence Cathedral, Italy, 15th century glass designed by Uccello, Donatello and Ghiberti
**St. Andrew's Cathedral, Sydney, Australia- early complete cycle of 19th century glass, Hardman of Birmingham.
**Coventry Cathedral, England, mid 20th century glass by various designers
**Brown Memorial Presbyterian Church, extensive collection of windows by Louis Comfort Tiffany

Houses

Stained glass windows in houses were particularly popular in Victorian era and many domestic examples survive. In their simplest form they typically depict birds and flowers in small panels, often surrounded with machine-made "cathedral glass", which, despite what the name suggests, is pale-coloured and textured. Some large homes have splendid examples of secular pictorial glass. Many small houses of the 19th and early 20th centuries have leadlight windows.
* Prairie style homes
* The houses of Frank Lloyd Wright

Public and commercial use of stained glass

Town halls, schools, colleges and other public buildings often incorporate stained glass or leadlighting.

* Public houses — In Britain, traditional pubs make extensive use of stained glass and leaded lights to create a comfortable atmosphere and retain privacy.
* Sculpture

Gallery of windows

Details

References

* Theophilus, "On Divers Arts", trans. from Latin by John G. Hawthorne and Cyril Stanley Smith, Dover, ISBN 0-486-23784-2
* Elizabeth Morris, "Stained and Decorative Glass", Doubleday, ISBN 0-86824-324-8
* Sarah Brown, "Stained Glass- an Illustrated History", Bracken Books, ISBN 1-858-91157-5
* Painton Cowen, "A Guide to Stained Glass in Britain", Michael Joseph, ISBN 0-7181-2567-3
* Lawrence Lee, George Seddon, Francis Stephens, "Stained Glass", Spring Books, ISBN 0-600-56281-6
* Simon Jenkins, "England's Thousand Best Churches", Allen Lane, the Penguin Press, ISBN 0-7139-9281-6
* Robert Eberhard, "Church Stained Glass Windows", [http://www.stainedglassrecords.org/home]
* Cliff and Monica Robinson, "Buckinghamshire Stained Glass", [http://www.bucksstainedglass.org.uk/]
* Stained Glass Association of America, "History of Stained Glass", [http://www.stainedglass.org/html/SGAAhistorySG.htm]

ee also

*Architectural glass
*Beveled glass
*Cathedral glass
*Cathedral architecture of Western Europe
*Float glass
*Glassblowing
*Glass art
*Glass beadmaking
*
*Lead came and copper foil glasswork
*Leadlight
*Poor Man's Bible
*Rose window
*Stained Glass Sculpture
*Stained glass - British glass, 1811-1918
*Stained glass artists
*Tiffany glass
*Venetian glass

External links

* [http://www.cr.nps.gov/hps/tps/briefs/brief33.htm Preservation of Stained Glass]
* [http://www.stainedglassrecords.org/home.asp?NOC=NOC Church Stained Glass Window Database] , covering ~2800 churches in the southeast of England
* [http://www.stainedglassmuseum.com/ The Stained Glass Museum] (Ely, England)
* [http://www.StainedGlassHowTo.com/ Stained Glass How To] , an on-line magazine devoted to helping people learn the craft of Stained Glass.
* [http://www.vidimus.org/ Vidimus] , an on-line magazine devoted to medieval stained glass.
* cite web |publisher= Victoria and Albert Museum
url= http://www.vam.ac.uk/collections/glass/stained_glass/sacred_stained_glass/index.html
title= Sacred Stained Glass
work= Glass
accessdate= 2007-06-16