RELIEVO, or RELIEF, in SCULPTURE, &c. is the projection or standing out of a figure which arises prominent from the ground or plane on which it is formed; whether that figure be cut with the chisel, moulded, or cast.
There are three kinds or degrees of relievo, viz. alto, basso, and demi-relievo. The alto-relievo, called also haut-relief, or high-relievo, is when the figure is formed after nature, and projects as much as the life. Basso-relievo, bass-relief, or low-relievo, is when the work is raised a little from the ground, as in medals, and the frontispieces of buildings; and particularly in the histories, festoons, foliage, and other ornaments of friezes. Demi-relievo is when one half of the figure rises from the plane. When, in a basso-relievo, there are parts that stand clear out, detached from the rest, the work is called a demi basso.
In architecture, the relievo or projection of the ornaments ought always to be proportioned to the magnitude of the building it adorns, and to the distance at which it is to be viewed.