half binding

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

• noun A bookbinding in which the back and often the corners of the volume are bound in a material differing from the rest of the cover.

from The Century Dictionary.

• noun See binding.

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

• noun book binding in which the spine and part of the sides are bound in one material and the rest in another