Two different binding methods determine the way in which each sheet is folded and then called a stick to form a book, which further determines the arrangement of the page numbers on each sheet. The general page number is recommended for saddle stitches, page numbers. More flat nails, general printed nails, more formal flat nails. Flat nails, that is, wire flat nails. After folding the printed pages into a booklet, the printed pages are nailed with a wire on the side of the nail, and then the binding method of the cover is wrapped. Used for binding books in general. Saddle stitching, when it is bound, the folded page is like the action of the saddle on the horse, and it is placed on the refining strip moving around the binding machine. After the binding, the nail is placed on the horse's back. Therefore, open the book to see the middle part, you can find that the whole book is centered on the middle nail, the first page and the last page of the book are symmetrically connected, and the middle two pages are also symmetric and connected.