Painting with color on glass and the use of enamel.
The excessive use of opaque paint was not so much a new departure as the exaggeration of a tendency which had grown with the growth of glass painting itself. The really new thing in glass painting about this time was the introduction of enamel.
When glass painters were resorting, not only to opaque painting, but to abrasion, annealing, or whatever would relieve them from the difficulty of getting in mosaic glass the pictorial effect which was more and more their ruling thought, when glazing had become to them a difficulty (to the early glass workers it was a resource), it was inevitable that they should think about painting on glass in colour. Accordingly towards the middle of the sixteenth century they began to use enamel. This was the decisive turning-point of the art.
In theory the process of painting in enamel is simple enough. You have only to grind coloured glass to impalpable dust, mix it with "fat oil", or gum-and-water, and paint with it upon white or tinted glass ; in the furnace the medium will be fired away, and the particles of coloured glass will melt and adhere, more or less firmly, to the heated sheet of glass to which they have been applied. This theory glass painters began to put into practice. In the beginning they used enamel only tentatively, first of all in the flesh tints. It had been the custom since the fourteenth century to paint flesh always upon white or whitish glass in the ordinary brown pigment; and something of the simple dignity and monumental character of old glass is due, no doubt, to that and similar removedness from nature. Gradually the fashion was introduced of painting the flesh in red instead of brown. In one sense this was no such very new thing to do. The ordinary brown pigment spoken of all along is itself enamel, although it has been thought better not to speak of it by that name for fear of confusion.
Inasmuch, however, as this was the use of a pigment to get not merely flesh painting but flesh tint, that is to say, colour, it was a step in quite a new direction. Pictorially it offered considerable advantages to the painter. He could not only get, without lead, contrast of colour between a head and the white ground upon which it was painted, or the white drapery about it, but he could very readily give the effect of white hair or beard in contrast to ruddy flesh, and so on. There is a fragment at the Musee des Arts Decor atifs at Paris, attributed to Jean Cousin, 1531, in which a turbaned head appears to have been cut out of a piece of purplish-blue glass, the flesh abraded, and then painted in red, the lips still redder, whilst the beard is painted on the blue, which shades off into the cheeks in the most realistic manner. Very clever things were done in this way, always in the realistic direction; but down to the middle of the century, and even later, there were always some painters who remained faithful to the traditional cool brown colour. A rather happy mean between warm and cold flesh is found at Auch (1513), where warmish enamel upon grey-blue or greenish glass gives modelling and variety of colour in the flesh, which is yet never hot. Well-chosen pieces of glass are made use of, in which the darker half comes in happily for the bearded part of a man's face. So, also, the head of the Virgin at the foot of the cross is painted upon grey, which tells as such in her coif, shaded with a cooler brown, but only deepens and saddens her face, and intensifies the contrast with the Magdalen. Occasionally one of these heads comes out too blue, but at the worst it is better than the hot, foxy flesh painting which became the rule.
Painting in colour upon glass could naturally not stop at flesh red. It was used for pale blue skies, at first only to get a more delicate gradation from pale pot-metal colour to white, but eventually for the sky throughout the picture. In connection with yellow stain it gave a green for distant landscape.
Enamel was used in ornament to give the colour of fruits and flowers in garlands and the like, and generally for elaboration of detail, which, if not trivial, was of small account in serious decoration. For a while there were glass painters who remained proof against its seduction. It was not till the latter half of the sixteenth century that glass painters generally began seriously to substitute enamel for pot-metal, and to rely upon paint, translucent as well as opaque. Even then they could not do without pot-metal, avoid it as they might. The really strong men, such as the Crabeth Brothers, at Gouda, by no means abandoned the old method, but they relied so much upon paint as to greatly obscure the glory of their glass. The Gouda windows, which bring us to the seventeenth century, contain among them the most daring things in glass extant. They prove that a subject can be rendered more pictorially than one would have conceived to be possible in glass, but they show also what cannot be done in it; in fact, they may be said to indicate, as nearly as can be, the limits of the practicable. What artists of this calibre could not do we may safely pronounce to be beyond the scope of glass painting, even with the aid of enamel.
No skill of painting could make otherwise than dull the masses of heavily painted white glass employed to represent the deep shade of the receding architecture in the upper part of the window on page 242 ; so, the mass of masonry which serves in the lower half of the window on this page as a background to the Donor and his patron saint and some shields of arms, represented as it is by a thick scum of brown paint, could not but lack lustre. Think of the extent of all that uninteresting paint; what a sacrifice it means of colour and translucency !
Enamel painting did not lead to much. The colours obtained by that means had neither the purity nor the richness and volume of pot-metal. They had to be strengthened with brown, which still further dulled them ; and, the taste for light and shade predominating as it did in the seventeenth century, the glass painter was eventually lured to the destruction of all glass-like quality in his glass.
There are some windows in the cathedral at Brussels, in the chapel opposite that of the Holy Sacrament, where are Van Orley's windows, which bear witness to the terrible decline that had taken place during something like a century, not that they are badly executed in their way. The texture of silk, for example, is given by the glass painter perfectly ; but, in the struggle for picturesque effects of light and shade, all consistency of treatment is abandoned. The painter is here let loose ; and he can no more withstand the attractions of paint than a boy can resist the temptation of fresh fallen snow. The one must throw snowballs at somebody, the other must lay about him with pigment. Here he lays about him with it recklessly. He is reckless, that is, of the obscurity of the glass he covers with it. At moments, when the sun shines fiercely upon it, you dimly see what he was aiming at; nine-tenths of the time all is blackness. Slabs of white glass are coated literally by the yard with dense brown pigment through which the light rarely shines.
It had become the practice now to glaze a window mainly in rectangular panes of considerable size. Where pot-metal colour was used at all, it had of necessity to be surrounded with a leaden line ; but within the area of the coloured mass the leading was usually in these upright and horizontal lines, and not at all according to the folds of the drapery or what not. If the glazier went out of his way to take a lead line round a face, instead of across it, that was as much as he would do; if it was merely the face of a cherub, however delicately painted, he would, perhaps, as at S. Jacques, Antwerp, cut brutally across it; and even where structural lead lines compelled him to use separate pieces of material, he by no means always took advantage of the opportunity of getting colour in his glass, but, as at Antwerp, contentedly accepted his rectangular panes of white, as something to paint onto the exclusion of no matter how much light. It simplified matters, no doubt, for the painter thus to throw away opportunities, and just depend upon his brush; but it resulted at the best only in an imitation of oil painting, lacking the qualities of oil paint.
The French glass painters were less reckless. At Troyes, indeed, there is plenty of seventeenth century glass in which a workman can still find considerable interest. That of Linard Gontier, in particular, has deservedly a great reputation. He was a painter who could get with a wash of colour, and seemingly with ease, effects which most glass painters could only get at by stippling, hatching, and picking out; and he managed his enamel very cleverly, floating it on with great dexterity. But it is rarely that he gets what artists would call colour out of it. Even in the hands of a man of his prodigious skill the method proclaims its inherent weakness. The work is thinner, duller, altogether poorer, than the earlier glass of much less consummate workmen, who worked upon sounder and severer principles. The strength and the weakness of the painter are exemplified in the group of Donors above.
The painting is admirable, not only in the heads, but in the texture of the men's cloaks; those cloaks, however, are painted in black paint. When the light is quite favourable they look like velvet; they never look like glass.
There is here the excuse, for what it may be worth, of texture and perhaps other pictorial qualities. Even that is often wanting in seventeenth century work, as when, at S. Jacques, Antwerp, the background to a design in white and stain is glazed in panes of white glass solidly coated with brown paint. This is obscuration out of pure wilfulness.
It was not only when the artist sought to get strong effects in enamel painting that the method fell short of success. The delicacy that might be got by means of it was neutralised by the necessity of some sort of glazing, and matters were not mended by glazing the windows in panes. It is impossible to take much satisfaction in the most delicately painted glass picture when it is so scored over with coarse black lines of lead or iron that it is as if you were looking at it through a grill. That is very much the effect seen in Sir Joshua Reynolds' famous -window in the ante-chapel at New College, Oxford (two lights of which are shown opposite), where the Virtues are seen imprisoned, you may say, within iron bars. They look very much better there than in the glass, which, for all the graceful draughtsmanship of the artist and the delicate workmanship of the painter, is ineffective to the last degree. It has no more brilliancy or sparkle than a huge engraving seen against the light; square feet of white glass are muddied over with paint.
It was not Sir Joshua's fault, of course, that the traditions of the glazier's craft were in his day well-nigh extinct; but Sir Horace Walpole was quite right when he described these vaunted Virtues as "washy". To say that they are infinitely more pleasing in the artist's designs is the strongest condemnation of the glass.
There was one use made of enamel which promised to be of real help to the glazier, that of painting the necessary shadows on pot-metal in shades of the same colour as the glass. Since enamel of some kind had to be used, why not employ a colour more akin to the glass itself than mere brown? It would seem as if by so doing one might get depth of colour with less danger of heaviness than by the use of brown ; but the glass painted in that way (by the Van Lingen, for example, a family of Flemings established in England, whose work may be seen at Wadham and Balliol Colleges, Oxford) was by no means free from heaviness. Enamel then, it will be seen, was never really of any great use in glass painting, and it led to the degradation of the art to something very much like the painting of transparencies, as they are called, on linen blinds.
Let us note categorically the objections to it. A glazier objects to it, that it is an evasion of the difficulty of working in glass, and not a frank solution of it. That may be sentimental more or less. A colourist objects to it, because it is impossible to get in it the depth and richness of strong pot-metal, or the brilliancy of the more delicate shades of self-coloured material. That, it may be urged, remains to be proved, but the enamel painter practically undertook to prove the contrary, and failed. Admirers of consistency object to it, that it succeeds so ill in reconciling the delicacy of painting aimed at with the brutality of the glazing employed. That, again, is a question of artistic appreciation, not so easily proved to those who do not feel the discord. Lovers of good work, of work that will stand, object to it that it is not lasting. This is a point that can be easily proved.
The process of enamel painting has been explained above (page 77). The one thing necessary to the safe performance of the operation is that the various glass pigments shall be of such consistency as to melt at a lower temperature than the glass on which they are painted. That, of course, must keep its shape in the kiln, or all would be spoilt. The melting of the pigment is, as a matter of fact, made easier by the admixture of some substance less unyielding than glass itself, such as borax to make it flow. This "flux", as it is called, makes the glass with which it is mixed appreciably softer than the glass to which it is apparently quite safely fixed by the fire. It is thus more susceptible to the action of the atmosphere ; it does not contract and expand equally with that; and in the course of time, perhaps no very long time, it scales off. Excepting in Swiss work (to which reference is made in Needle Point in Glass Making.) this is so commonly so, that you may usually detect the use of enamel by the specks of white among the colour, where the pigment has worked itself free, altogether to the destruction of pictorial illusion. And it is not only with transparent enamel that this happens, but also with the brown used by the later painters for shading.
The brown tracing and painting colour was originally a hard metallic colour which required intense heat to make it flow. The glass had to be made almost red-hot, at which great heat there was always a possibility that the pigment might be fired away altogether, and the painter's labour lost. In the case of the thirteenth century painter's work the danger was not very serious. Thanks to the downright and sometimes even brutal way in which he was accustomed to lay on the paint, solidly and without subtlety of shade, his work was pretty well able to take care of itself in the kiln. It was the more delicate painting avoid all possibility of any such catastrophe. The easiest way which was most in danger of being burnt away; and in proportion as men learnt to carry their painting further, and to get delicate modelling, they became increasingly anxious to of doing this was (as in the case of transparent enamel) to soften this colour with flux. That enabled them to fire their glass at a much lower heat, at which there was no risk of losing the painting, and they were able so to make sure of getting the soft gradations of shade they wanted; and the more the painter strove to get pictorial effects the more he was tempted to soften his pigment; but, according as the flux made the colour easier to manage in the fire, it made it less to be depended upon afterwards; and the later the work, and the more pictorial its character, the more surely the painting proves at this date to have lost its hold upon the glass. In many a seventeenth century window the Donors were depicted in their Sunday suits of black velvet and fur, the texture quite wonderfully given; now their garments are very much the worse for wear, more than threadbare. The black or brown is rich no longer, it is pitted with specks of raw white light; sometimes the colour has peeled off en masse. Time has dealt comparatively kindly with the gentlemen on page 81, but in the glass there is an air of decay about their sable cloaks which takes considerably away from their dignity. It is one characteristic of enamelled windows that they do not mellow with age, like mosaic glass, but only get shabby.
Any one altogether unacquainted with the characteristics of style is apt to be very much at fault as to the date of a window. The later windows are in so much more dilapidated a condition than the earlier that they are quite commonly mistaken for the older.
It has to be borne in mind that most of the devices adopted by the glass painters, the use, namely, of large sheets of fragile glass, and the avoidance of strengthening leads, no less than the resort to soft enamel, whether for colour or for shading, all go to make it more perishable.
It may be said that the decay of the later painting is due not so much to the use of enamel as to the employment of soft flux. That is true. But when it comes to the painting of texture and the like, the temptation to use soft colour has generally proved to be irresistible. One is forced to the conclusion that the aim of the later glass painter was entirely wrong; that for the sake of pictorial advantages, which went for very little in a scheme of effective church decoration, even if they did not always detract from the breadth of the work, he gave up the qualities which go at once to make glass glorious, and to give it permanence. Whatever the merits of seventeenth century glass painting they are not the merits of glass; there is little about it that counts for glass, little that is suggestive of glass except the breakages it has suffered.
What is said of seventeenth century glass applies also to that of the eighteenth century, only with more force. Sir Joshua and Benjamin West were quite helpless to raise the art out of the slough into which it had fallen, for they were themselves ignorant of its technique, and did not know what could be done in glass. It was not until the Gothic revival in our own century, and a return to mosaic principles, that stained glass awoke to new life.
This is Enamel Painting.
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