Editing Donatello (section)

==Work involving glass==
[[File:Virgin and childVAglass (cropped).jpg|thumb|Modern glass moulded in a cast of the ''[[Chellini Madonna]]'']]
Donatello's inventiveness and search for new effects is shown by his various, mostly novel, uses of glass, a material hardly used in European sculpture before. He was commissioned to design [[stained glass]] for Florence Cathedral around 1434, a conventional task, but one usually given to a painter rather than a sculptor.<ref>Coonin, 123-125.</ref> He used glass in [[tesserae]] form in the backgrounds of reliefs, including the Prato pulpit and ''cantoria'' reliefs,<ref>Coonin, 118-119; Seymour, 94; Olson, 78.</ref> which was an old style, but his background of a network of roundels with glass-covered wax and gold inlays for the terracotta [[Piot Madonna]] (Louvre, c. 1440 or later) is original.<ref>Coonin, 202-203.</ref> 

His [[Chellini Madonna]] (c. 1450, [[Victoria and Albert Museum]]) is a round bronze relief, 28.5 cm across, which is cast at an even thickness, meaning that the reverse has an intaglio (concave) image matching the convex relief one on the front. This seems to have been intended to be used as a mould for molten glass and perhaps other materials.  Donatello gave it to his doctor and friend Giovanni Chellini in 1456, though it was probably not new at that point.<ref>Coonin, 199-202.</ref>