Guidebook Page 48-49 Extra Information

Standing in All Saints North Street experiencing the light diffusing through the surviving medieval glass is to be transported back in time to the Middle Ages, provoking a sense of wonder and mystery. These images are but fragments of what once existed across Medieval Britain. Sadly, the destruction of religious imagery in the Reformation has meant that all too few windows survive from this period. In around 1540, on the eve of the Reformation, the creation of stained glass windows was a vibrant and important industry employing large numbers of skilled craftsmen; yet, within twenty years this had essentially ceased to exist.

Whilst we use the term “stained glass”, actually for the most part we are looking at images which have been painted directly onto the glass and at All Saints North Street we see some of the finest examples of medieval art to have survived.

The industry had two separate components: the glass makers and the glass painters. By the later medieval period these represented two distinct crafts. The process of making a window started with a patron, who provided the funds for a new commission. The high costs involved in producing a single window meant that only the wealthiest in society could afford such work, such as the family of Nicholas Blackburn. Alternatively, we see families working together to fund a window, as we see in the Pricke of Conscience window which was funded by three families, or the religious guilds may raise the funds for a particular window.

The creation of a window started with the patron who would commission a new window from the glaziers. Glass painters had established themselves in the major towns and cities; in York they were concentrated around St Helen’s Church in Stonegate. The patron, or their executor, would choose the images to be depicted in the glass and often had themselves commemorated in the base of the window. The window serves as both a memorial to the donor(s), but the work was also seen as a religious act of devotion, which would be expected to count as good deeds towards their salvation.

Once the imagery was chosen, the work would be detailed in a written contract which would include the price. Complex commissions may also include drawing of the imagery (called vidimuses), but these rarely survive. The window would be drawn as a full-sized cartoon on a board or parchment in the glaziers’ studio – this would show details such as the leadwork and colour scheme. The individual pieces of glass would then be cut to fit the cartoon, and create the window, which was painted in the studio.

The glaziers bought sheets of glass from the glass-makers who were based in the wooded areas around the Weald in South-East England. A few medieval kiln sites are known from excavation such as Blunden's Wood, Hambledon, Surrey. Glass is made by melting sand. Adding wood-ash into the kiln lowered the temperature at which the silica melts and beech was particularly favoured. The resulting glass has a greenish tinge. Chemicals could be added to produce different colours, although we cannot be certain that any coloured glass was produced in medieval England, so this may have been imported from the Continent.