In our era of rapid prototyping and 3D printing, technologies that promise to transform the production of everything from medical devices to skyscrapers, it is easy to lose sight of how three-dimensional objects came into being in the predigital age. One way into this question is through drawing. What role did it play in the production of Renaissance sculpture, some of the most ambitious and technically accomplished ever produced? Or, as Columbia University art historian Michael Cole puts it, “Why did sculptors draw?”

his is the problem at the center of “Donatello, Michelangelo, Cellini: Sculptors’ Drawings from Renaissance Italy,” currently on view at the Isabella Stewart Gardner Museum in Boston and co-curated by Mr. Cole and Oliver Tostmann, formerly of the Gardner and now Curator of European Art at the Wadsworth Atheneum in Hartford, Conn.