Of Mosaic in wood, that is, of Tarsia; and of the Compositions that are made in Tinted Woods, fitted together after the manner of a picture.
§ 100. Inlays in Wood.
How easy a thing it is to add some new discovery to the inventions of the past, is clearly shown to us, not only by the aforesaid fitted pavement, which without doubt comes from mosaic work, but also by these same tarsias and the figures of many different things, that closely resembling mosaic and painting have been made by our elder artists out of little pieces of wood, variously coloured, fitted and joined together in panels of walnut. This is called by the moderns ‘lavoro di commesso’ (inlaid work) although to the elder artists it was tarsia. The best specimens of this work were to be found in Florence in the time of Filippo di Ser Brunellesco and afterwards in that of Benedetto da Maiano, who, however, strangely enough judged tarsia a useless thing and completely abandoned it as will be told in his Life. He, like the others of past times, executed tarsia in black and white only, but Fra Giovanni of Verona who was very proficient in the art improved it greatly, giving various colours to the woods by means of dyes in boiling water and of penetrating oils, in order to produce the lights and shadows with these variously tinted woods, as in the art of painting, and skilfully putting in the high lights by means of the very white wood of the silio.[[260]] This work began in the first instance with designs in perspective, because the forms in these end with plane angles, and the pieces joined together showed the contours, and the work appeared all of one flat piece, though it was made up of more than a thousand. The ancients worked however in the same manner with incrustations of fine stones: as is plainly seen in the portico of St. Peter’s, where there is a cage with a bird and all the details of the wooden bars etc., on a ground of porphyry inlaid with other different stones.[[261]] But, because wood is more pliant and much more amenable for this work, our masters have been able to make more abundant use of it and in the way that best pleased them. Formerly for making the shadows they used to scorch the wood with fire on one side, this imitated shade well; but others afterwards have used oil of sulphur and corrosive sublimate and preparations of arsenic, with which substances they have obtained the hues that they desired, as is seen in the work of Fra Damiano in San Domenico in Bologna.[[262]] And because such a line of work consists only in the choice of designs that may be adapted to it—those containing blocks of buildings and objects with rectangular outlines to which force and projection can be lent by means of light and shade—it has always been exercised by persons possessing more patience than skill in design. And thus it is that though many things have been produced in this line, such as representations of figures, fruit, and animals, some of which are in truth most life-like, yet since it is a work that soon becomes black and does not do more than counterfeit painting, being less than painting, and is also of short duration because of worms and fire, it is considered time thrown away in vain to practise it, although it may indeed be both praiseworthy and masterly.[[263]]
CHAPTER XVIII. (XXXII.)
On Painting Glass Windows and how they are put together with Leads and supported with Irons so as not to interfere with the view of the figures.
§ 101. Stained Glass Windows; their Origin and History.
Formerly the ancients were in the habit of filling in their windows, but only in the houses of great men, or of those at least of some importance, in such a manner as to prevent the wind or cold from entering, while not excluding the light. This plan was adopted only in their baths and sweating rooms, vapour baths and other retiring rooms, and the apertures and vacant places of these were closed with transparent stones, such as onyx marbles,[[264]] alabasters, and other delicate marbles that are variegated or that incline towards a yellowish tint. But the moderns, who have had glass furnaces in much greater abundance, have made the windows of glass, either of bull’s-eyes[[265]] or of panes, similar to or in imitation of those that the ancients made of stone; and they have fastened them together and bound them with strips of lead, grooved on both sides, and furnished them and secured them with irons let into the walls for this purpose, or indeed into wooden frames,[[266]] as we shall relate. Whereas at first the windows used to be made simply of clear bull’s-eyes with white or coloured corners, afterwards the artists thought of making a mosaic of the shapes of these glasses differently coloured and joined after the manner of a picture.[[267]] And so refined has the skill in this art become, that in our days glass windows are seen carried to the same perfection that is arrived at in fine pictures upon panel, with all their harmony of colour and finish of execution, and this we shall amply show in the Life of the Frenchman Guglielmo da Marcilla.[[268]]
In this art the Flemings and the French have succeeded better than the other nations, seeing that they, with their cunning researches into pigments and the action on them of fire, have managed to burn in the colours that are put on the glass, so that wind, air, and rain may do them no injury, whereas formerly it was customary to paint windows in colours coated with gum and other temperas that wasted away through time and were carried off by the winds, mists, and rains, till nothing was left but the mere colour of the glass. In the present age, we see this art brought to that high grade beyond which one can hardly desire further perfection of fineness and beauty and of every quality which contributes thereto. It supplies a delicate loveliness not less beneficial to health, through securing the rooms from wind and foul airs, than useful and convenient on account of the clear and unimpeded light that by its means is offered to us.
In order to produce such windows, three things are necessary, namely, luminous transparency in the glasses chosen,[[269]] beautiful arrangement in that which is worked out with them, and clear colour without any confusion. Transparency is secured by knowing how to choose glasses that are clear in themselves, and in this respect French, Flemish, and English glasses are better than the Venetian,[[270]] because the Flemish are very clear and the Venetian much charged with colour. In clear glasses when shaded with darker tints the light is not totally lost, they are transparent even in their shadows, but the Venetian, being obscure in their nature and darker still in their shadow, lose all transparency. Again many delight in having the glasses loaded with colours artificially laid on so that when the air and sun strike upon them, they exhibit I cannot tell how much more beauty than do the natural colours; nevertheless, it is better to have the glasses clear in their own substance, rather than obscure, so that when heavily coloured they may not be left too dim.