Delectable” isn’t usually the first word that comes to mind at a scholarly exhibition of the art of the past, but it seems both irresistible and completely appropriate for “Della Robbia: Sculpting with Color in Renaissance Florence,” a collaboration between the Museum of Fine Arts, Boston, and the National Gallery of Art, Washington, now on view in D.C.1 The illuminating, eye-testing, beautifully installed exhibition surveys the work of three generations of the celebrated Tuscan family who invented a new kind of glazed terracotta sculpture in the fifteenth century and became known internationally for their polychrome pieces. The della Robbias’ work is defined by sensitively modeled figures, usually in shining white against rich cobalt blue backgrounds, accented with the radiant yellow, green, and purple of the exquisitely rendered garlands of leaves and fruit surrounding the images. From a distance, della Robbia reliefs and sculptures are striking and sumptuous. From a close view, a wealth of enchanting, ravishingly colored detail reveals itself. Delectable.

As a helpful family tree at the start of the installation makes clear, the patriarch, Luca della Robbia (1399/1400–82), originally a sculptor in marble, began experimenting with glazed terracotta—“cooked earth”—about 1440. He developed a new way of using riverbed clay for ceramic sculpture, modeling or molding and firing forms, and then glazing them with special preparations and a special double firing process to produce exceptionally brilliant, opaque, gleaming surfaces. The highly colored reliefs, plaques, and sculptures in the round created with this method were gorgeous,