Despite their robust modeling, they seem schematic, as do many of the images of young blondes that follow, paintings by such masters as Filippo Lippi, Sandro Botticelli and the Pollaiuolo brothers, and suave marble busts by Desiderio da Settignano and Andrea del Verrocchio.

WSJ: The Renaissance Portrait | From Out of a Featureless Crowd | By Karen Wilkin