GILDING. - The use of gilding on objects, sculptures, and architecture dates back to the most remote antiquity.
The absolutely primordial operation was that of covering objects with extremely thin sheets of gold; only later did the use of leaf gilding come into practice, which was simpler and less costly. The application or fixing process varied according to the material to be covered. With metal, the mercury amalgam passed over with heat was used; with marble, egg white; and with wood, an embryonic varnish known as *leucophorum*. In medieval and modern art, as is known from sources (Theophilus, *Schedula diversorum artium*; Cennini, *Il libro dell’arte*; and Cellini and Vasari), the application of gilding did not differ greatly from that of antiquity.
It was especially in use among painters, who prepared the backgrounds of their panels with gold; among carvers, who gilded frames, tabernacles, and other ecclesiastical furnishings; and among sculptors, who thus finished many of their bronze works. A noteworthy example, recently confirmed by cleaning, is the bronze doors of Ghiberti for the Florentine Baptistery.