34. Queen of Sheba, Fairford.
The second intermediate method of staining glass began earlier to affect the design and execution of windows; and the character of fourteenth century glass is distinctly modified by it; and, curiously enough, whilst flashing applied to red and blue glass, this applies to yellow.
It was discovered about the beginning of the fourteenth century that white glass painted with a solution of silver would take in the kiln a pure transparent stain of yellow, varying, according to its strength and the heat of the furnace, from palest lemon to deepest orange. Observe that this yellow stain is neither an enamel nor a pot-metal colour, but literally a stain, the only stain used upon glass. In pot-metal the stain (if it may be so called) is in the glass, this is upon it. But it is absolutely indelible; it can only be removed with the surface of the glass itself; time has no more effect upon it than if the glass were coated with yellow pot-metal. This silver stain was not only of a singularly pure and delicate colour, compared to which pot-metal yellows were hot and harsh, but it had all the variety of a wash of water-colour, shading off by imperceptible degrees from dark to light, and that so easily that the difficulty would have been in getting a perfectly flat tint.
Moreover, it could be as readily traced in lines or little touches of colour as it could be floated on in broad surfaces. By its aid it was as easy to render the white pearls on a bishop’s golden mitre as to give the golden hair of a white-faced angel, or to relieve a white figure against a yellow ground—and all without the use of intervening lead.
35. S. GREGORY, ALL SOULS’ COLLEGE, OXFORD.
It is not surprising that such a discovery had a very important effect upon the development of the glass painter’s practice. By means of it were produced extraordinarily beautiful effects, as of gold and silver, peculiarly characteristic of later Gothic work. The crockets and finials of white canopies would be touched with it as with gold, the hair of angels and the crowns of kings; or the nimbus itself would be stained, the head now being habitually painted on one piece of white glass with the nimbus. The crown and the pearl-edged head-band of the Queen of Sheba, from Fairford, ([page 50]), are stained upon the white glass out of which the head is cut. In the figure of S. Gregory on [page 51] the triple crown is stained yellow, and so is the nimbus of the bull, whose wings also are shaded in stain varying from light to dark.