A book whose text block is complete and serviceable (and usually in reasonably good condition), but contained within a binding that is defective or incomplete. The term suggests that the book is suitable for rebinding. Note: Technically, what we call bindings on most books today, where the text block is glued in (in a hardcover book the text block is glued to a cover by some mull and end sheet paper, and in a softcover book normally the text block is glued directly to the spine of the cover), is actually a casing. Traditionally, bindings were actually sewn to the collected gatherings. The two terms- Binding and Casing – are, becoming interchangeable today).
The image shows a binding copy of The Essence of Malone by George Hardinge. All signatures are present and are fit for stitching and binding.