What you most enjoy in it is the distribution of white and colour; and you enjoy it most when you do not too curiously examine into the detail of the design, when you are satisfied to enjoy the colour, and do not look for form, which after all is of less account in glass.
So far as effect only is concerned, quarry work, the mere glazing in squares, answers in many places (such, for example, as the clerestories of narrow churches, where you could not possibly enjoy any detail of design that might be there) all the purpose of grisaille; and it was commonly resorted to. But the painting upon such quarries counts for very little; it is far too small and fine in detail to have any effect further than to tone the glass a little, which would have been unnecessary if the glass employed had been less clear. In fact, delicate paint on distant clerestory glass is much ado about very little; and one cannot help thinking that plain glazing would there have answered all the purpose of the most delicately painted pattern work. The fourteenth century glaziers seldom complicated their quarry work by the introduction of bands or straps of colour between the quarries, or by the introduction of colour other than such as might occur in rosettes or shields and so on, planted upon them, rather than worked into the design. Occasionally, however, as at Châlons-sur-Marne, you come upon an ornamental window ([page 167]) in which quarries are separated by bands of clear white, a certain amount of colour being introduced in the form of yellow quarries substituted at regular intervals for the white. On the [same page] is another coloured diaper window designed on quarry lines, also at Châlons. In that quarries of white and yellow are separated by a trellis of blue. Something of the sort is to be seen also at S. Radegonde, Poitiers.
123. Regensburg.
In these cases the painting, as will be seen, is strong enough to hold its own at a considerable distance from the eye, but the effect is not very happy. When, by the way, it was said that delicate painting on distant quarries was lost, it was not meant to imply that strong painting on quarries would be a happy solution of the difficulty. As a matter of experience, it is seldom satisfactory. On the other hand, the common expedient of leading up the coloured backgrounds to figure work in small squares of ruby, green, and so on, was generally the means of securing good broken colour.
124. Munich Museum.