A flattened relief that allows for the rendition of convincing, infinite recession into space through optical illusion rather than actual projection. This technique was introduced by Donatello in the 15th century. Among the works he created in relievo schiacciato is his St. George Slaying the Dragon, the relief on the base of his statue of St. George (1415-1417) at Orsanmichele, Florence. In this work, the details of the foreground protrude some-what from the background stone but, as the image moves away from the viewer, the carving becomes flatter and flatter, until it seems as if drawn with the chisel. Both Desiderio da Settignano and Michelangelo used relievo schiacciato in their sculptures. Desiderio's Virgin and Child (c. 1460) in the Philadelphia Museum and Michelangelo's Madonna of the Stairs (1489-1492) in Casa Buonarroti, Florence, are rendered in this technique.
Historical dictionary of Renaissance art. Lilian H. Zirpolo. 2008.