Mixed media study using paper, pencil, watercolor and gesso of a windmill in motion. A tondo (plural "tondi" or "tondos") is a Renaissance term for a circular work of art, either a painting or a sculpture. The word derives from the Italian rotondo, "round." The term is usually not used in English for small round paintings, but only those over about 60 cm (two feet) in diameter, thus excluding many round portrait miniatures.