In publishing, spine lean is the degree to which a book’s spine is not perfectly perpendicular to the book’s covers. The term is generally used when discussing the condition of used books, as a book that has been read multiple times is likely to have some degree of spine lean. While spine lean is not generally considered a defect, it can affect a book’s value, particularly if the degree of lean is severe.
There are a few different causes of spine lean. The most common is simply reading the book multiple times, as the pressure of holding the book open can cause the spine to gradually bend. Another common cause is storing the book in an environment that is not conducive to its long-term preservation, such as a humid basement or a sunny windowsill. Poorly made books are also more likely to develop spine lean, as the spine is not as strongly glued to the cover boards.
The degree of spine lean is typically described in terms of how far the spine has deviated from the perpendicular. For example, a book with a spine that is leaning at a 10 degree angle would be said to have a 10 degree spine lean.
A spine lean is the degree to which a book’s spine is tilted when the book is resting on a flat surface. The purpose of spine lean is to ensure that a book’s pages are properly opened and that the text on the pages is legible.
Spine lean is important for both books and publishing. It allows books to be stored neatly on shelves, and it also makes it easier for readers to find the book they want to read. In addition, spine lean makes it easier for publishers to keep track of inventory and to ship books to retailers.