Vasari only ever credited him with paper impressions of his nielli, rather than engravings made from special printing-plates, in the usual sense of the word; in fact there probably never were any such engravings by him. Although he clearly was an important artist of his time, few surviving works, and no surviving prints, can now be definitely attributed to him, so scholarly interest in him has greatly reduced. Over 100 drawings in the Uffizi, and others elsewhere, remain attributed to him.