Generally, hardcover photo albums are lined with double rings. Paperback books also have a single ring lining, but the ring lining page is not a folded two-page paper, but a single page, which is generally called lining paper.
Extended data
Butterflies evolved from folding clothes after putting them on. In the process of long-term reading of folded books, the folds of folded books often break, and after the break, one page after another appears, which gives people inspiration and gradually appears a page-based binding system. The first album book that appeared was Butterfly Clothes.
Butterfly clothes appeared in the late Tang Dynasty and prevailed in the Song Dynasty. It is a binding form that the printed surface of the page is folded in half according to the middle seam, then the pages of the book are aligned according to the middle seam, glued to another wrapping paper with paste, and finally cut into volumes. Books bound with "butterfly clothes" are called "butterfly clothes" because they look like butterflies flapping their wings and dancing.
A total of 130 volumes have been submitted for the five generations of block printing. Since it is called Raiders, it must be a prescription book. Because scrolls are called "volumes", they are not called books. In addition, in the Tang Dynasty, some classics written by the Tang people were loaded with butterflies, so the classics of the Five Dynasties should be loaded with butterflies.
Baidu encyclopedia-butterfly suit