A printed label attached to the spine of a book's binding, most often used for the title. The title may be a shortened version of the book's title as-printed on the title page. Spine labels are typically leather or paper and glued to the spine.
The image shows three cloth bindings with paper spine labels. The first is lacking part of the label. The second is toned. The third wraps around to include the front cover and it remains well-preserved.