Will Durant in his “Story of Civilization” wrote of Chinese pottery, “What survives is the memory of an art perhaps as completely lost as that of medieval stained glass.”
Which leads me to ask, how did we lose medieval stained glass art? Don’t we still have stained glass today? What are we missing? Are some special methods lost, and if so, why the big deal, since can’t we use our brainy brainy modern scientist types to figure out the composition and make it just as good?
I think Will was either mistaken, or overstating his case. I do not recall reading anywhere else about any “lost” facets to medieval stained glass craftsmanship.
It’s very possible that many of the Medieval Stained glass techniques have indeed been lost. Modern “Stained Glass” is really just leaded glass - windows made from many different pieces of colored glass held together with lead came. True stained glass has images etched into the pieces, a beautiful and time-consuming process that is rarely, if ever, used anymore.
I don’t know the answer to your question, but I’d like to point out that knowing the composition doesn’t tell you how to put the constituent elements together. For an extremely simple example, consider that a no-bake cheesecake requires cream cheese, Jell-O, condensed milk, butter, and ginger snaps. Knowing that doesn’t tell you how to make one.
There are definitely colors the formula to which has been lost, like Chartres blue.
I find this statement very odd. Stained glass in the traditional sense has been very active in recent times. If anything it has been extended over the years. Certainly there are cheap shortcuts that obviate some of the more labour intensive aspects if you want to be save money and time, but I can’t think of anything that is truly lost. There have been some stunning stained glass windows created in the last 50 years. Of course the main purchasers of such windows have been churches, and municipal buildings, and modern buildings have often seen fit to be designed with very modern aesthetics that find traditional stained glass anachronistic, and also too expensive. So the idea of stained glass window craftsperson as a career option, and a phone book with listings of such people is not exactly commonplace. But it certainly remains.
In the more crafty world, leadlighting remains a popular pastime, and the supply of beautiful glass for this purpose remains strong. In many ways much of this material is too complex and much more suited to smaller works than traditional stained glass.
A friend of mine is one of the foremost Ecclesiastical stained glass artists in the country,
and she does beautiful work, but she never does actual etching of images in the glass, and I doubt that she is familiar with the technique (although I’ve never asked her).
I don’t understand the claim – we have contemporary books telling how they made and colored the glass and performed the various operations. Heck, I have a peperback copy of one such book. Much stained glass was “painted” with glass composition that was then baked into place – a process that’s still done today. And plenty of people etch glass today (although I’ve never heard of anyone etching stained glass). AFAIK, there are no “lost” techniques for stained glass. But I’m not an expert on this.
Etching of glass is only done when there is a flashing of colour over either clear or another colour. The most common colour to etch was red - as red used gold in its composition it was much more expensive and thus flashing of colour rather than solid colour was typical for red. Etching was usually done with hydrofluoric acid - which is evil in the extreme. At least it can now be mechanically abraded easily.
As was noted above, one of the underappreciated and critical skills is not the handling of the colours, but the painting on, and firing of the black/brown metallic material to form the drawn components of the design. The skills in managing a difficult material and process to meld well with the overall colours and light is hard won.
So can we accurately recreate medieval stained glass using the same techniques they did?
I very much doubt that there are any secrets (as far as the colors are concerned)-we can analyze the old glass down tp parts per billion-so finding what elements are used for various colors is trivial.
