high relief

from The American Heritage® Dictionary of the English Language, 5th Edition.

• noun Sculptural relief in which the modeled forms project from the background by at least half their depth.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A form of classical sculpture in which forms extend from the background by at least half of their depth.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a sculptural relief in which forms extend out from the background to at least half their depth