Various, Blackwood's Edinburgh Magazine…
“ The differences of position and light, by their distinct requirements, separate the three styles of relievo, the alto, basso, and mezzo. It is not, as many suppose, that the basso, the lower relief, is less finished than the alto, or high relief; the finish of each is differently placed. "In the highest relief, however decided the shadows may, and must of necessity be, on the plane to which the figure is attached, the light on the figure itself is kept as unbroken as possible ”
