A Lecture on Stained Glass

by Robert Anning Bell

The practical function of stained glass is comparable with that of mosaic. Mosaic is an enrichment of the shadow. Buildings designed for mosaic usually have quite small windows, low down in the big domes or sparsely set in the side walls, and it is the mosaic enrichment of shadow, vaguely lit by reflected light from these windows, which gives it its highest beauty. The peculiar charm of mosaic depends largely on the gold treatment of the background, which is infinitely more attractive when seen on curved surfaces and lit from below.

Stained glass is a method of glorifying and modifying the light which enters a building; it has a wide range, from a limpid clarity to rich and even sombre depths. Its power of emotional suggestion is considerable and this, doubtless, commended it to the mediaeval mystics.

The spiritual function of stained glass is, like that of mosaic, by a noble beauty of treatment, to present elevated ethical and religious ideas in a worthy way. It may do this by means of symbolism, or by typifying virtues and moral qualities by individual figures of great characters from mythology or from religious history. For symbolism and these type-figures it is peculiarly suited. Further, its function is to enhance and to deepen the mood of religious exaltation which the architecture of the building has already suggested to the worshipper. Stained glass is essentially a method of strengthening, carrying further and enriching the mood in which the worshipper finds himself when he enters those noble buildings, so full of the sense of aspiration and exaltation, and of the mystery which lies behind the outward show of things. That is just by way of showing you the sort of attitude which, I believe, we should adopt towards stained glass. You must realise that your work is more than making pleasant and agreeable colour and striking a casual note of beauty. You have more than that to carry out, and deeper feelings to express.

Now to come down to the material, to what is called stained glass. The fact is it is merely coloured glass. It is glass melted and mixed up in the pot with various coloured oxides, green, blue or red, whatever you want. Then the blow-pipe is put in, and with a quantity of the sticky mixture attached to it is then blown out into a large bulb, just as ordinary window glass is, and cut off and flattened out on big tables to cool. The beauty of the quality of stained glass is very largely owing to the irregularity of the thickness of it, and you often get subtle variations in the colour, streaks, blotches of colour and so on; the thickness of the glass makes quite an appreciable difference in the depth of the colour, as you can easily imagine. One selects from the large sheet of glass the particular piece which contains a tone of colour one wishes to use.

Another treatment of glass is very largely used. This is called “flash” glass. It was found that if the glass were coloured right through with vigorous blues, ruby reds, and greens, it became so deep that you did not get enough light through it. So quite early they found out a method by which a film of colour could be applied to a sheet of clear glass, usually of a greenish tinge. You have the same thickness of glass as in the other method, but the colour is in a thin stratum on the surface of it. This “flash” glass has another advantage which we occasionally make use of; you can work away the thin veneer of colour, leaving only the dear glass, an obvious method for making patterns. It used to be done by means of a wheel with which you ground away the surface rather laboriously, now you stop out with Brunswick Black the parts you do not want to eliminate and apply acid—it is the same method as in etching—and when you get down to the clear glass you get rid of the acid. Then you can paint in your brown paint or yellow stain, and you get quite an attractive effect. You will often see it done in rich robes and in crowns and things like that; it is quite useful and workmanlike, but if it is used too much it becomes tricky and pretty.

Now for the practice of the craft. I am afraid this will be very commonplace talk to those students who are working at stained glass, but possibly some others will be interested. I particularly hope the more advanced painter students may be interested, for it is to them one rather looks to take to stained glass in the last years of their education when they have become fairly competent in drawing and design, that is the time when stained glass should become to them a very attractive and fruitful means of expression. The modern practice is extremely like the old practice. The craft has the great attraction to my mind of being one of those crafts which have changed very little all through the ages, and the workshop method of executing stained glass now is very much what it was in the earliest days.

The tools are very much the same, too, except that for cutting the glass nowadays we use the more convenient modern diamond. The old method was simple but rather laborious. When you wanted to cut out a piece of glass you got a rather stoutish iron wire which you made red hot, and you drew the iron wire over the lines you wanted to break, and then with another tool you just nipped it off all round. They did the most extraordinarily elaborate things in those days with these. I think they got towards the later period to be far too fond of showing off their skill. They cut most preposterous, irregular and odd shapes to show they could do them; it was a case of the skilful craftsman getting a bit beyond himself.

After the glass cutting comes the painting. This is done in the same way as it always was, and the leading too. There are several sizes of leads, 1/2 in., 3/8 in., and 1/4 in., etc. It is just a piece of narrow lead flanged in the middle to separate the adjacent pieces of glass, and when the lead is fixed all round the pieces, cement is put in to hold it together. You want to be a good plumber to do it very well, as I think our students have found out. I think all who practise the art should go through the workshop and learn to cut the glass and to lead it up; it is not a very serious part of their training; it is not necessary that they should become expert plumbers, but they should learn how and why it is done. I should very much like to have an expert plumber and an expert glazier to do that part of the work for the more advanced students, so that they could get on more quickly with advanced work. But I am afraid we shall not have that just yet, owing to the need for economy all round.

Now getting further on, I take it the earlier people designed their windows in a much more simple way than we do. They had no cartoons, I think. I believe that they set the work out on the long wooden bench on which the glass is laid to be leaded up and cut, and marked it out with charcoal. Very often they had to use up bits of glass they had got, and make the designs fit into these, as glass was very expensive. Again, the early work is generally based on geometrical forms. A tall window would be cut up into seven or eight diamonds, circles, quatrefoils, or such like; with ornamental detail in between. That gives an opportunity of using up very small pieces of glass. In those days labour was not very valuable and glass was, and so they did not like to waste any bits. Nowadays you cut a large sheet of glass, you get a few bits out of it, and often that is about all you can use of it. They had very few colours, and as you could not go very far wrong with a limited palette, I really think very much of the beauty of the earliest glass is because they could not help themselves. The earlier glass was glaziers’ work, it was the men thinking of leading it up rather than of the painter’s work, who made the design.

Then about 1300 somebody discovered that extraordinarily effective and useful material, the yellow stain. It was found that a solution of silver painted on the glass would give, according to its strength and according to the firing, all sorts of shades of yellow. This led them to escape from the coarse note in stained glass. Blues, reds and greens are very good as a rule, but the neutral colours are rather poor, the purples are not very good, and yellow is inclined to be coarse. The yellow stain was of great assistance, and they could get nearly all the yellows they wanted; it was very much more manageable because they could shade it off.