George Stubbs, Horse Attacked by a Lion, 1769
From the Tate Gallery:
Stubbs was obsessed with the subject of a lion attacking a horse, making at least seventeen works on the theme, most of which were in oil on regularly-shaped canvas. In this enamel on copper piece, Stubbs cut off the corners to form an irregular octagon, thus tightening the composition. The result is a forceful depiction which is perhaps his most successful treatment of the theme. This is Stubbs’s earliest known experiment in painting in enamel colours, and was the first time the technique - previously limited to decorative objects and miniature portraits - was used by an artist of Stubbs’s stature. He may have approached the medium out of scientific curiosity, although his exact reasons are not known. Before producing this piece, Stubbs spent two years studying the chemical changes to colours under high temperatures, and a further three years improving the support upon which the painting would be made. He used a copper plate support for this work, but was dissatisfied with the size limitations, and for later enamels commissioned the Master Potter Josiah Wedgwood to produce special large ceramic tablets.