Facts about Glass: Silver Stain

Silver stain, also known as yellow stain, is used to create a yellow colour on clear glass. The technique of silver stain was introduced to stained glass in the early 1300s and involves painting silver compounds (such as silver nitrate, chloride, sulphate or oxide) onto a piece of glass and then firing it in the kiln. Silver staining is the technique from which the term ‘stained glass’ derives

Silver stain is used on the Boppard windows and the details below are from the Siegfried von Gelnhausen panel – the top image highlighting the pages of a book and the bottom image colouring the beak and leg of the bird on the shield.

Siegfried von Gelnhausen panel - detail of book
Siegfried von Gelnhausen panel – detail of book
Siegfried von Gelnhausen panel - detail of shield
Siegfried von Gelnhausen panel – detail of shield

The technique of silver staining has not changed over the centuries: The pigment is combined with other ingredients such as clay and Venice turpentine to help the mixture lay smoothly on the glass surface. This is then applied to the back of the glass (after the painted details have been applied to the front). The process of heating the glass and stain in a kiln creates a chemical reaction between the stain and the glass, causing an ionic exchange between the glass and the silver to produce a range of yellows on the surface of the glass. These can range from a pale lemon to a dark orange. Unlike paint, which when heated becomes fused to the glass surface, the yellow stain actually becomes a part of the glass. Areas of stain can be applied to give hair colour, costume highlights, and to create details such as crowns and haloes, etc. From about the 15th century it has also been applied to blue glass to create greens for such things as foliage – all without having to add extra strips of lead. A fine example of this can be seen in the 15th century panel St John the Evangelist Hands the Palm to the Jew, on display in the Burrell Collection (below).

St John and the Jew - Detail of silver stain on blue glass
St John and the Jew – Detail of silver stain on blue glass
Burrell Collection - St-John the Evangelist Hands the Palm to the Jew
Burrell Collection – St-John the Evangelist Hands the Palm to the Jew

Detail of silver stain used on clear glass to create yellow and used on blue glass to create green.

Many factors affect the colour of stain produced, including the chemical composition of the glass, the composition of the stain, length of time in the kiln, temperature of the kiln, the thickness with which the stain was applied etc. In the medieval period it was not an exact science as they didn’t have the same technology for controlling the speed and temperature of a kiln when firing as we do now.

Boppard 8th Commandment panel - detail of foot
Boppard 8th Commandment panel – detail of foot

In the early days of using silver stain, the process of controlling the kiln temperature and all the other variables made silver staining difficult and expensive. Where possible, pot metal yellow glass would be used and silver staining applied only were necessary, as when you wanted just a patch of yellow on the glass section. The detail above is from the Boppard 8th Commandment panel – the feet picked out using black enamel paint.

Burrell Collection - Saint Writing
Burrell Collection – Saint Writing

This can also be seen in the French panel above with a Saint writing, seated in a Gothic niche with cusped pointed arch; he is seated on a yellow throne facing left, pen in one hand and the other steadying the book propped in front of him, dated to the 14th Century. The top of the lectern, the beard and other details are in silver stain but the seat and other large yellow areas are pot metal yellow.

As technology and experience developed, the cost of silver staining dropped and the cost of coloured pot metal glass increased. Because clear glass was so much cheaper than coloured glass small decorative clear glass panels using paint and stain became very popular, as can be seen in the two examples on display in the Burrell Collection, shown below.

Burrell Collection Roundel - Labours  of the Month - February
Burrell Collection Roundel – Labours of the Month – February

This is a very well-known and admired English Norwich School roundel dating to the 15th century, based on the “Labours of the month”. These were a monthly cycle of activities the peasants should be engaged in, such as; April – Planting and enjoying the country or picking flowers, May – Hawking and courtly love, June – Hay harvest, July – Wheat harvest, and August – Wheat threshing. The roundel above shows February – a man warming himself in front of the fire! It is thought to be from the same set as three roundels of the later 15th Century in the Victoria and Albert Museum (September, October and November) which may have been originally in St. Michael-at-Coslany Church. Norwich.

Burrell Collection - St. Barbara roundel
Burrell Collection – St. Barbara roundel

The roundel of St. Barbara above is Flemish, and was created in the early 16th century. St. Barbara is standing in a landscape, holding a book and feather; on the right is a tower (her main attribute), a round structure approached by a flight of steps with handrails and on the left, a fortress and church in a valley.

Facts about Glass: Sanguine and Carnation

In the late 15th or early 16th century an iron-based glass paint was developed called sanguine or carnation (sometimes also referred to as Jean Cousin Rouge). This pigment created shades of pink to red-brown on firing, and was mainly used for highlighting and reddening areas of the glass, such as lips, cheeks and for creating flesh tones on limbs.

The term sanguine is often used to describe a redder colour for highlighting cheeks and lips, while the term carnation is used to describe a lighter more subtle pink ideal for colouring the body. These pigments were in use until the 18th century, but during the 19th century they were replaced by a similar colour of enamel. [http://webh01.ua.ac.be/mitac4/jaas1997a.pdf].

The composition of both sanguine and carnation was very complex, and the recipes varied greatly. They are based around crushed hematite (a mineral form of iron oxide, also contained in blood). This is diluted in a little water, producing a red colour when crushed very finely, and brown if used in larger grains. “A historical and chemical study about glass painting ‘Rouge Jean Cousin’ (Jean Cousin Red)”, by O. Schalm, K. Janssens, F. Adams, J. Albert, K. Peeters and J. Caen, concluded that “the aim of the recipes was to separate the biggest pigment grains from the smaller ones, since only grains with a diameter of about 0.01 mum [micrometers] give the painting powder the red tint.” [http://www.bcin.ca/Interface/openbcin.cgi?submit=submit&Chinkey=170630].

There are some beautiful small silver stained panels that use sanguine and carnation on display at the Burrell Collection. Perhaps the best of these is the Flemish example below of an Allegorical Scene, dating to the 16th century. It shows ‘Conscience’ guiding a man past the vices of Avarice, Conceit, Jealousy, Melancholy and Pride.

Allegorical Scene - Flemish 16th century
Allegorical Scene – Flemish 16th century
Allegorical Scene - Titles
Allegorical Scene – Titles

In the centre, a bearded half-naked man walks clasping his hands in contrition (Homo); he gazes earnestly at another bearded naked man holding a chopper in one hand and a birch in the other (Conscientia) and he is followed by a young woman with clasped hands and bowed head (Tristitia); facing the man from the other side are an elderly fully draped woman (Avaritia), a young woman with wild expression and hand raised to her head (Opinio), and a woman biting a heart (Invidia); a large matron, wearing a peacock plumed helmet, with puffed chest and arms akimbo, follows on the right (Superbia).*

* The description of this object is from the catalogue, “Stained and Painted Glass – Burrell Collection” 1965.

The lower skirt of Tristitia is painted with sanguine to give it a redder colour, and the body of Conscientia is painted with carnation to give a good flesh tone, and it was used to paint the pattern on Suberbia’s cothing. Carnation was used to create the flesh colour, particularly noticeable on the figure of Conscientia.

Another lovely example on display is “A Virtue: Charity”, in which carnation has been used to delicately give a flesh tone to the face, arms, and legs of the figure of Charity (below).

Virtue  and charity

The detail below shows the area with carnation stain and the delicate little hatching used to create extra variation in tone  and three dimensional effect.

Virtue and charity - detail
Virtue and charity – detail

In art, Charity is often expressed as the love of God. Here, Charity holds a cross in one hand and a flaming heart in the other which depicts the love of God.

Depicting God

Depictions of God appear throughout art in the medieval period up until the Reformation, and can be seen in many stained glass panels and other objects based on a wide variety of Christian themes. God can be found represented as God the Father, God the Son or God the Holy Spirit, and different combinations of the three. The 8th Commandment panel from Boppard includes an image that appears to be of God the Father. He is shown emerging from a cluster of clouds, to demonstrate that he is in heaven. God holds the scroll with the 8th commandment written on it and is looking down benevolently upon the righteous.

Detail of God - Boppard 8th Commandment panel
Detail of God – Boppard 8th Commandment panel

The Annunciation panel from Boppard also contains an image of God. The Annunciation scene usually has a representation of God in one form or another. The Boppard Annunciation panel shows a smiling friendly God with a shaft of light bursting from him and a dove, representing the Holy Spirit which will become the baby Jesus, pointing towards Mary.

Detail - Boppard Annunciation panel
Detail – Boppard Annunciation panel

Depictions of God the Father with God the Holy Spirit, in the form of the dove, carrying out his work are  quite common, and can found in other depictions of the Annunciation in the Burrell Collection.

Detail - Nottingham Alabaster - Annunciation
Detail – Nottingham Alabaster – Annunciation

The Nottingham alabaster, shown earlier in the “Life of Christ and The Virgin panels –The Annunciation” blog, shows God with an excellent beard turning into a dove for the same effect.

Two more examples of the Annunciation scene in the collection are of interest, one a painted glass roundel with silver stain (a technique which we will be discussing later – see our glossary in the meantime), and one in ivory.

Annunciation roundel - South Netherlandish, dating to the early 16th century
Annunciation roundel – South Netherlandish, dating to the early 16th century
This ivory carving is a leaf from a diptych made in France in the 14th century
This ivory carving is a leaf from a diptych made in France in the 14th century

Both show God as the Holy Spirit in the form of a dove hovering above Mary. The roundel is South Netherlandish, dating to the early 16th century. The ivory carving is a leaf from a diptych made in France in the 14th century.

Finally there is an unusual depiction of the Holy Trinity. The alabaster above was carved in Nottingham, England, around 1400. It shows God the Father sitting on a throne and holding a napkin containing the souls of the saved above his crucified Son. Traces of red polychrome are on the lining of God’s robe and on his lips and traces of blue on his eyes. There is gilding on his crown and hair. Christ’s nimbus is red and black and the base has traces of green.

Alabaster Holy Trinity - English
Alabaster Holy Trinity – English

The depiction of God the Father with souls in a napkin in place of the Holy Spirit is quite rare in English alabaster carvings. There are three examples in the Victoria & Albert Museum and another in the Museum of Fine Arts, Boston [W.L. Hildburgh, ‘Iconographical Peculiarities in English Medieval Alabaster Carvings’, Folklore XLIV (1933), pp. 50-56, PL IV, Figs. 8&9].

The Burrell group is one of the finest English alabaster carvings, possessing a solemnity and grandeur rarely seen in English late Gothic sculpture.

Depicting the Devil

Depictions of the devil were extremely popular across all forms of medieval art, and stained glass was no exception! The way in which the devil is depicted varies greatly, as there is a great variety of symbolism and characteristics associated with it. Such images were often used as a warning to churchgoers about the consequences of doing wrong.  This was almost certainly the case in an interesting depiction of the devil, hovering over the heads of wrong doers, in the Eighth Commandment panel from Boppard. It has an imp-like face and goat-like hooves and seems to be encouraging the condemnations in the scene beneath him. The man in the bottom right points accusingly at the rich and prosperous man on the left. Two men behind him join in the denouncement with accusatory body language and expressions. The facial expressions are beautifully painted, with different hairstyles and clothing.

Detail from 8th Commandment panel
Detail from 8th Commandment panel

Alongside the devil in the Boppard panel a number of other depictions in stained glass on display in the Burrell Collection are significant. These include two small Swiss roundels, both of a slightly later date than the Boppard glass.

In the “Scenes from the Life of Saint Francis” roundel there is a complete depiction of hell, with the devil and several devilish assistants in a fiery underground scene. The roundel is only about 150mm across and has exquisitely detailed paint, stain and enamel work. It is dated 1671 and signed by the glazier Michael Muller IV of Zug, beside Lake Zug and about 25 miles south of Zurich. In this depiction the devil is shown with wings, horns and a tail against a fiery background.

Glass roundel - Scenes from the Life of Saint Francis
Glass roundel – Scenes from the Life of Saint Francis
Detail from Scenes from the Life of St Francis-
Detail from Scenes from the Life of St Francis-

Another little Swiss roundel dated to the 17th century and displayed next to the St.Francis roundel shows St. Notker Balbulus, (Notker the Stammerer), giving the devil, in the form of a green and blue dog with yellow horns, a good thrashing. So much so that he has broken his rod. Notker was a musician, author, poet, and Benedictine monk at the Abbey of Saint Gall in modern Switzerland, living around the period 840-912. His biographer, Ekkehard IV, also a monk from the same Abbey but living some 140 years later, described him as “delicate of body but not of mind, stuttering of tongue but not of intellect, pushing boldly forward in things Divine, a vessel of the Holy Spirit without equal in his time”. According to legend, Notker Balbulua on entering the church one night, found the Devil there in the shape of a dog; he ordered him to stand still and, grasping a stout cudgel which had once belonged to Saint Columbanus, he broke it over the demon’s back [from “The Story of the Devil” By Arturo Graf].

Glass roundel of Notker Balbulus
Glass roundel of Notker Balbulus

The devil is also often depicted as a dragon, which is associated with many stories including that of Saint Margaret of Antioch. There are two sculptures of Margaret of Antioch on display in the Burrell Collection. The limestone sculpture below is French and dates to around 1500. The dragon is chained and Margaret has her foot in its belly. The detail shows a close-up of the devil/dragon’s head.

Margaret of Antioch - French 1500
Margaret of Antioch – French 1500
Detail Margaret of Antioch - Dragon's Head
Detail Margaret of Antioch – Dragon’s Head

The story goes that Margaret was the daughter of a pagan priest who, on the death of his wife, had her nursed by a pious Christian woman. Margaret became a Christian and vowed to remain a virgin for her faith, which caused her father to disown her. Working as a shepherdess, she continued to live with her nurse who adopted her. A wealthy and powerful man became obsessed by her beauty and asked her to renounce her faith and marry him. When she refused, he had her tortured which resulted in some miraculous incidents. One involved her being swallowed by the devil in the shape of a dragon, then being regurgitated when her crucifix irritated the dragon’s insides. Apparently, she was put to death in 304 AD. She was declared apocryphal by Pope Gelasius I in 494, but was and still is venerated in various parts of the world.

Margaret of Antioch in Oak - South Netherlandish
Margaret of Antioch in Oak – South Netherlandish
Detail Margaret of Antioch in Wood - Dragon
Detail Margaret of Antioch in Wood – Dragon

The above version of Margaret is carved in oak and thought to be a South Netherlandish copy of an original, now in the Musee Gruuthuse, Bruges. Unchained, the devil again feels Margaret’s boot!