Saddle stitch binding is the method for the binding together, using a wire (for example) from the center of the cover to the gutter, both of the covers and all of the signatures (the printed sheets folded to the size of a book) that made up the contents of the book in such a way that, when opened, the pages would be in sequence.
The process of bookbinding is a simple one; the structure of a booklet that can be opened to the gutter is used for weekly magazines, photography magazines, and comic books. It is appropriate for bound matter with a limited number of pages; because the spine is the folds of the pages, letters (such as the book’s title) cannot be put on it.
The imposition (the process of positioning pages on the printed sheet) used for Saddle stitch binding is different from that used with other binding methods. Because the first half and the second half of the booklet are composed symmetrical around an axis defined by its center, it is essential to carefully consider the printing sheets and the printing method from the planning stage.