In case binding, the compressing of the pages of a book prior to casing-in. The pressure generated during smashing causes the pages of the book to press very close together, forcing out air, and have a "nesting" or packing effect, which makes the thickness of a book less than the total thickness of all the pages separately. Smashing also compensates for thread build-up. (See Bulk.) Smashing, as opposed to nipping, involves the application of pressure to the entire surface of a book block. See also Nipping and Case Binding.