Religion and art have seemingly always gone hand-in-hand, especially for Catholicism. Commissions for artwork by the church served many purposes; to give a visual depiction of a particular story, to educate the illiterate, dogma, and simply the pure beauty of the artworks at hand. Paintings, tapestries, sculptures; many have stood the test of time and been analysed, interpreted and deconstructed by students of both religion and art, and provided immense wonder and joy to those who stand in the presence of such masterpieces.
Perhaps one of the most fascinating and invariably beautiful of these mediums, is that of the stained-glass window. Light is symbolic in many religions, so it only makes sense that this would be harnessed to bring religious art to life.
Stained-glass windows are created by cutting glass into appropriate shapes and fusing them together with lead, creating a latticework which is called ‘came’. Impurities in glass cause the different colours, hence early glass manufacturers figured out that by adding different metals they could manipulate the results, allowing for a spectrum of different colours. Eventually, artists realised that this method was expensive and impractical, and opted instead for painting neutral-coloured glass. Unfortunately, the colours of these windows deteriorated much quicker than the previous method.
These days, glass is much cheaper and cutting glass is far easier to do. You can probably take a lead-lighting course at your local community centre; a luxury many of the early artists would not have had available to them.
Some of the oldest stained-glass windows are unfortunately under threat from our modern environment and climate. Even throughout various wars, many stained-glass windows were left relatively unharmed, which is either because of their removal and storage in safe places, or sheer good luck. Air pollution and humidity are a significant threat against these beautiful art works. Acid rain, grime build-up and temperature fluctuations also pose a risk to the longevity of stained glass.
Double-glazing is a practical means to protect the glass. As I am sure you would be aware if you’ve ever considered getting your own windows double-glazed, this can help to insulate your home, and would do the same for the stained-glass. It keeps the glass away from the elements, and hence will help to prevent an erosion. In 1861, England’s York Minster was equipped with double-glazing, only with the intention of insulating the building. In turn, this process has definitely helped to preserve the beautiful stained glass. The key is to leave a small gap between the window and the glazing, where humidity can be controlled, much like between a painting and its protective glass in a gallery.
Double-glazing however only offers protection to one side of the window. The other side is subject to modern heating systems; which medieval churches were obviously never built to withstand. Another suggested protective method would be to create a controlled micro-climate around these windows, independent of the heating system inside the church. This is potentially impractical due its complexity and costs, but in order to preserve these stunning artworks, it may be necessary and worthwhile.
Despite the conservation efforts in place, my suggestion would be for anyone who is interested, make sure you give yourself the opportunity to see these amazing windows around the world before the deteriorate to the point of illegibility.
Elliott, Sara. 2008. How Stained Glass Works. http://entertainment.howstuffworks.com/arts/artwork/stained-glass.htm
Frenzel, Gottfried. 1985. The Restoration of Medieval Stained Glass. http://www.icomos.org/publications/93stain5.pdf
2016. The Lead Came Technique. http://www.freepatternsforstainedglass.com/lead-came.html