(7) _The Quality of Glass and the Colours Used._--At first these differ little from those used in the previous period, but as the fourteenth century proceeds, the rich intense reds and blues, with their "streakiness," their endless variety of tone and texture, which makes each piece of glass a jewel with an individuality of its own, and needing no enrichment, give way to glass of a thinner, flatter quality. In Plate III. Mr. Saint has managed to catch and the printer to reproduce something of the quality of these early blues. There is a change too in the proportions of the colours used. The colour schemes of the Early Period are almost always conceived on a basis of red and blue, but now green and yellow become equally important; Plates XXI., XXII., for example, contain very little blue at all. The canopies when not white are mainly yellow, and this alone is responsible for a very large amount of yellow in the colour scheme--too much, in fact, as a rule. The yellow used at first, till silver stain took its place, was, as I have said, a rather hot unpleasant pot-metal. The green of the First Period had been a rather sharp brilliant colour, used generally in small quantities, and striking a high shrill note among the deep reds and blues, like a clarionet in an orchestra. The typical green of the fourteenth century, on the other hand, which is often used as a background, is a greyer duller colour altogether. Plate XVI. and Plate XXI. give a fairly good idea of its quality. [Sidenote: White glass for flesh.] Another change, which was the natural result, both of the increased amount of white now used in windows and of the introduction of the silver stain, was the gradual substitution of white glass in the flesh of figures for the brownish pink formerly used. Its use afforded an opportunity for getting white in amongst the colour, and so helping to bind the design together, and the fact that the hair, crowns, and mitres of figures could now be stained yellow, rendered it on the whole the most suitable glass for the purpose, and we find it holding the field down to the late sixteenth century, when a pinkish enamel began to be used. [Illustration: PLATE XXVII BOSSES, FROM PLATE XXV] [Sidenote: Painted diapers.] (8) _The use of Painted Diaper Patterns on the Coloured Backgrounds._--The red and blue backgrounds to the figures in the twelfth and thirteenth centuries needed no further decoration. Their own depth and quality was enough in itself, but the thinner, flatter tones that succeeded them needed enriching and giving texture to, in order to throw the figures up into proper relief; or so the fourteenth century artist seems to have felt, for from the beginning we find his backgrounds usually covered with a diaper painted in enamel.