The glass that has been hitherto mentioned is that which, like the true enamels, is coloured in the making with metallic oxides, the painting on it being confined to the use of the brown shadow colour, and the yellow silver stain. Windows made wholly in that way can be described as painted glass because though the silver is a true stain, it is used as paint and fired, instead of being incorporated with the glass in the pot. About the middle of the sixteenth century, the practice came into vogue of using panes of transparent glass as surfaces for decorative design in painted colours or in grisaille, and large windows of square panes of white glass with elaborate designs of arabesque ornament were done in verifiable enamel colours and with a minimum of leading, such as those in the Laurentian Library, Florence (Fig. 219). The medallion in the centre contains the arms of the Medici, the family of Pope Clement VII, whose tiara and keys accompany the arms in another of the same series of windows that has been reproduced in Mr. Lewis Day’s admirable book, _Windows_. A very remarkable school of enamelled glass painting that largely concerned itself with heraldry existed in Switzerland, encouraged by the custom which had grown up of persons and guilds presenting painted windows to each other. These largely consisted of portrait subjects accompanied by armorial bearings. Into this work the use of the point entered to a surprising extent, the washes of colour being frequently covered with the scratched lines with which details were drawn or textures indicated with the minuteness of fine engraving. Indeed the process of obtaining effects by drawing with a needle in lines of light through a dark medium inevitably suggests the art of etching on metal. [Illustration: FIG. 219.--Painted Window in the Laurentian Library, Florence. Sixteenth Century.] Marvellous as were the effects produced by the needle in the hands of a master the method was a dangerous one under less capable control, and in any case the effect is altogether different and less glass-like than that of the earlier method, being characterized by a sharp glittering brilliancy in place of the deep effulgence of pot metal. [Illustration: FIG. 220.--Drawing for Stained Glass, Victoria and Albert Museum.] This painted glass of the sixteenth century contains much fine vigorous heraldic drawing, as may be seen in the working drawings that are extant, as well as in the windows themselves, Burgmair and many others, whose power in heraldic art is well-known in other directions, having also made designs for the glass painters. Fig. 215 is a characteristic sketch of lions supporting banners and shields, a favourite method of grouping in compositions of this kind. The vigour and “go” of these animals is very remarkable, and it is unfortunate that the artist’s name is not on the drawing. [Illustration: FIG. 221.--Drawing by Holbein, Victoria and Albert Museum.]