Stained Glass

From the 12th to the 15th century the technique of stained glass remained practically unchanged, though one minor innova tion had a great effect on the character of design. This was the invention, early in the 14th century, of a yellow stain derived from a solution of silver. It formed a very thin film on the glass and was therefore very transparent ; on clear glass it varied in tone from pale lemon yellow to deep orange ; but it could also be applied to blue glass to produce a brilliant green. Its effect on design was far-reaching and will be noticed when we come to the history of the craft. In the 16th century the technique of glass painting became more scientific ; the glass itself was thinner and smoother and more transparent ; two layers of different colours could be put together to produce a third colour; if these layers were fused together, one layer could be ground away or "abraded" (and by a later process "eaten" away by fluoric acid) to give delicate effects beyond the reach of a leaded mosaic. Finally, towards the middle of the 16th century, the art of painting in enamel on glass appeared, perhaps as a result of economic causes which made a scarcity of pot-metal. Hitherto glass had been coloured throughout its substance and was known as "pot-metal," though to obtain sufficient translucency in a dark colour like ruby the glass was "flashed," that is to say, clear glass whilst still pliant was dipped into molten coloured glass, and so received a translucent film of the desired colour. But now ground glass was mixed with various metallic oxides (copper for green, cobalt for blue, manganese for purple, and so on) and the design was then painted on to a clear sheet of glass and fused on. For some time this technique was continued with the old technique of leaded pot-metal; but in the 17th and 18th centuries the old technique disappeared, and the art of stained glass was virtually dead.

Eleventh and Twelfth Centuries.

The windows at Augs burg, ascribed by Fischer to the middle of the iith century, have already been mentioned. To the end of the 11th century belongs a window at Le Mans (France) painted with the Ascension. For the 12th century we have in England a figure from a Tree of Jesse in the minster at York, and at Canterbury there is a mag nificent series representing the genealogy of Christ which may be dated about 1180. At Chartres there are more important and extensive examples—in the west window is a Tree of Jesse design which is undoubtedly the best surviving stained glass of this century ; also the beautiful figure of the Virgin and Child known as La Belle Verriere. Other considerable specimens of 12th cen tury glass exist at Angers, Saint Denis, Chalons-sur-Marne, Bourges, Strasbourg, Poitiers and Le Champ (Isere). The earliest of these windows, such as those at Augsburg and Chartres, are strongly Romanesque in character. The windows at Canterbury come at the end of the Romanesque tradition. They still preserve the monumentality so characteristic of Romanesque design, but the figures are far removed from the rigorously schematic treat ment of the Augsburg prophets; there is the first flush of human ism in their bold features. There is a sense of movement in their

limbs ; a sense of vigour in the formal draperies. The colouring of this Canterbury glass is still typical of the 12th century; the bare flesh is cut in pink glass, whilst the rest of the design is a quiet harmony of blues, pale green, white, brown and yellow, arranged in fairly broad masses with no effort towards "jewel like" quality. The architectural settings are rudimentary, in most cases representing a simple column on each side of the figure, with an arch spanning the head.

It is probable that most of the early windows were of the single figure, monumental character of the Augsburg and Canterbury examples. But about the middle of the 12th century a new type of window came into being which consisted, instead of a single representative figure, of a medallion (or several medallions) painted with pictorial subjects, such as incidents from the life of Christ, or from the life of some saint. This change was ac companied by various subsidiary developments. The necessity of telling a story in a series of medallions led to the decorative arrangement of these medallions within an "armature" or iron framework which was itself a subject for pattern, and very beautiful designs were evolved, showing a skilful counterplay of circles, lozenges, quatrefoils and squares, with their appropriate borders and interspaces. This development in its turn neces sitated larger windows and this necessity had a profound effect on the development of Gothic architecture itself. A third develop ment was in the actual colour of the glass. The pictorial treat ment called for a more detailed and more varied play of colour, and the technical resources of the glass-maker were equal to this demand. The result was that kaleidoscopic or jewel-like glow of colours with which stained glass is always popularly associated. It is in glass of the early 13th century that this property is supremely evident.

Thirteenth Century.

With these early 13th century medal lions we first become fully conscious of the part played by the actual painting in stained glass. It is true that the earlier figures had a broad effective scheme of drawing, but with the 13th century medallions a fine dramatic sense of line was developed and continued in force throughout the century. And with the sense of line came that superb sense of dramatic composition illustrated in so many of the medallions of this period at Canter bury, Lincoln, Chartres, Sens, Bourges, Le Mans, Rouen, Cologne, Marburg and Klosterneuburg (near Vienna). The highly stylicized motives of the decorative borders of the izth century were no longer in keeping with this dramatic mode, and as the century advances we accordingly get a naturalizing of these motives. The formal acanthus leaves of classical inspiration give place to more natural plant motives, to scrolls of oak and vine ; these coil with a more organic and vigorous movement, until eventually, in the 14th century, the artists begin to copy directly from their own observation—from the ivy and the wild strawberry.