VETRATA. — Precursors of that kind of transparent mosaic which is the stained-glass window were the closures of basilican windows in the 4th and 5th centuries, formed of geometric panels of selenite and latticework (see the examples in S. Sabina in Rome).
Toward the end of the 10th century, stained-glass windows were employed with metal supports and lead framing. Colored glass in the mass was cut with a red-hot iron; the designs and chiaroscuro were executed with copper oxide in black strokes and fixed by successive firings. Among the co-
among whom Michelino da Besozzo, the Zavattari, Paolino da Montorfano, and Stefano da Pandino rivalled the French and German masters, heirs to the Gothic tradition; the same may be said of fra' Bartolomeo di Pietro, to whom the immense choir window of S. Domenico in Perugia is owed (1441). Later, however, a new chromatic brilliance appeared in Bologna in the windows of S. Petronio, based on cartoons by Michele di Matteo di Panzano and Lorenzo Costa, and those of S. Giovanni in Monte, based on designs by Francesco del Cossa. During the second phase of the work on Milan Cathedral, lasting until about 1515, classicizing realism prevailed through Niccolò da Varallo, Cristoforo De Mottis, and Antonio da Pandino, who also worked in the Certosa of Pavia. Above all the masters of the 16th century, however, excelled the Dominican monk Guglielmo di Marcillat, a native of Berry, with a stylistic breadth derived from Raffaello and Michelangelo, and a great richness of chromatic gradations simulating easel painting. To him are owed the windows of S. Maria del Popolo in Rome (ca. 1509), with a predominance of gray chiaroscuro, and other works in Cortona and, above all, in Arezzo Cathedral, with vivid tones of crimson, chrome yellow, water green, and ash-blue (1519 and following years). Marcillat founded a genuine school in Tuscany, composed, in addition to his heir Pastorino da Siena, who executed the great rose window on the façade of that cathedral after a design by Perin del Vaga, of Stagio Sassoli and Lorenzo Borro d'Arezzo, and the Cortonese Maso Porro and Michelangelo Urbani. In the first half of the 16th century, the grotesque-painted works executed by Giovanni da Udine for the Laurentian Library were highly esteemed in Florence; the same pupil of Raffaello is credited with the eight windows, decorated with arabesques on a white ground, in the Certosa of Ema (1520), rich in exceedingly delicate tonalities. While in Italy the Mannerist and Baroque tastes proved fatal to the practice of this art, in Germany it continued during the 17th century, even in private architecture, with abundant use of “grisailles,” heraldic elements, and garlands of flowers and fruit. As in other ornamental manifestations, in the revival of stained glass 19th-century Europe practiced a pedantic reproduction of the ancient until William Morris, in the full flowering of the Pre-Raphaelite movement, achieved a new synthesis of lines and colors in the windows of the chapel of Jesus College, Cambridge, based on designs by the painter Burne Jones. Subsequently, distinctive windows appeared especially in France and England in the Art Nouveau or floral style, until, in the first decades of this century, the restoration of the ancient principles—which ensured the stained-glass window’s luminous function through the purity of its colors—infused a new originality into its conceptions and visual effects. Among other examples, memorable in Rome was the work of Cesare Picchiarini, who worked from cartoons by Vittorio Grassi, Umberto Bottazzi, and above all Duilio Cambellotti to compose examples of lyrical exaltation in linear rhythms and harmonies of violet, amaranth red, Havana, pearlescent, and silvery tones, as attested, in the sacred sphere, by the Franciscan window, the Crucifixion window for Orvieto Cathedral, and the more complex and imposing triad adorning the Church of the Flagellation in Jerusalem (1929). — Vedi tavv. CXXXVII-CXXXIX.