Donatello which had been used for his work at Prato and Padua. So far the small bronzes made were from studies for larger works of sculpture, but about this time intense interest began to be taken in the remains of Greek and Roman art, and no doubt it was the increased importance attached to the antique bronze figures, mostly household gods of the Greeks, Etruscans, and Romans, that first led the principal Renaissance artists to turn their attention to similar work. From this time on, for a century and a half, these bronze figures were regularly made. The existing figurines may be broadly classified in four divisions, namely, the Paduan and Florentine figures executed prior to 1525; those of the school of Michelangelo; those of the Venetian school headed by Sansovino; and those of Giovanni di Bologna and his school. Leaving out of consideration the small ornaments for inkstands, vases, etc., the little animals, and the purely commercial imitations, chiefly Venetian, made at the end of the sixteenth century, the total number of Renaissance bronzes now known is roughly six thousand. Of these under a hundred are from models for larger works by Ghiberti, Donatello, Verrocchio, Lionardo, Michelangelo, and a few lesser lights; about two thousand represent original designs specially prepared for bronze production; some three thousand five hundred are duplicates of, or slight variations from, these originals, executed by pupils or near contemporaries of the masters; and the balance of four hundred or so, are direct reproductions of, or variations from, antique sculptures. Naturally all collectors aim for the first two sections, but the third section contains many fine bronzes, often close to the originals, with equally good patinas. They vary greatly, though they are all ascribed in commerce to the artists responsible for the originals.