Initially trained as a goldsmith, the stocky, durable Verrocchio considered himself a sculptor first and then a painter. His decisive, midcareer transition from painting to sculpture was probably a preference and not, as Vasari suggested, a retreat. Certainly, his contemporaries admired him foremost as a sculptor, an unrivalled metal caster and engineer. Only in his late twenties, but industrious and diligent, when he opened his independent business, he proved to be an excellent foreman, coordinating the activities of a self-contained shop in accord with time-tested, old-fashioned modes of operation. For sculpture (even relatively small works), he employed the centuries-old assemblage technique, in which many separate pieces were cast and then welded together – every major project involving the contributions of numerous hands.

The collaborative atmosphere and multitasking demands of his shop benefited scores of artists who passed through it, including Perugino and the sculptor Francesco di Simone Ferrucci. Leonardo and Lorenzo di Credi may have been the only assistants who remained for a decade or more; many other workers probably came and left on an “as needed” basis. Leonardo, no doubt, thrived in this environment and would have been galvanized by the challenge of learning so many diverse skills. However, the detailed, sometimes factory-like approach could be a bit stultifying for some, such as Lorenzo di Credi, who, like many Florentine artists, had first apprenticed with a goldsmith. As a painter, he excelled in the small parts but could never quite grasp the whole. Even the generally respectful Vasari had to admit that the well-intentioned Credi was punctilious to a fault.