Figure 21 : Flashing of red glass . Detail of window from the Abbey of Saint- Germain-des-Prés ( c . 1243 – 48 )
Medieval glass c . 1250 – 1500
Observed together , the medieval windows at Winchester College show the stylistic and technical development of stained glass over the late Middle Ages : from the origins of the Rayonnant style in Paris , through the flourishing of fourteenth-century English glazing design , to the last period of Gothic glass in England .
I . The scene of St Germain ’ s death is typical of the glass produced in the early to midthirteenth century in France . This is often exemplified by the windows of Sainte- Chapelle , made in Paris around the same time as those of the Abbey of Saint- Germain-des-Prés . It has in fact been suggested that one of the glaziers of the Winchester scene also worked at Sainte- Chapelle . 14 Both sets of windows are in the Rayonnant style , a type of Gothic architecture that was characterised by large windows , the size of which allowed for more extensive and complex narrative glazing programmes .
Held together by lead strips , each piece of glass is one colour . This technical limitation means the detail is fairly simple . Most of the pieces are made of ‘ pot-metal glass ’, meaning they are coloured throughout by metallic oxides added to the molten glass beads . Red and blue pot-metal glass is often too dark to allow light through . It is therefore lightened by applying a thin layer of the coloured glass over a sheet of clear glass in a process called ‘ flashing ’. This can be observed near the bottom of the scene ( fig . 21 ), where parts of the red glass have chipped away , revealing the clear glass beneath .
Medieval Glass at Winchester College 15