ALTO-RELIEVO (Ital. for “high relief”), the term applied to sculpture that projects from the plane to which it is attached to the extent of more than one-half the outline of the principal figures, which may be nearly or in parts entirely detached from the background. It is thus distinguished from basso-relievo (q.v.), in which there is a greater or less approximation in effect to the pictorial method, the figures being made to appear as projecting more than half their outline without actually doing so. At the same time it is not only the actual degree of relief which is implied by these two terms, but a resultant difference also of design and treatment necessitated by the contingent differences of light and shadow. (See Relief and Sculpture.)