The waist seal, also known as the waist of a book, means "putting a tape-like text introduction in the middle of the book to cooperate with marketing or book recommendation". "How to make an appetizing waist" is one of the marketing requirements of books, and the waist seal exists for the promotion and marketing of books. A girdle with exquisite design, consistent with the overall style of the book and accurate propaganda language is very necessary for a book trying to become popular in the market.

Its length includes front cover, back cover, spine and front and rear cuffs, and its height is flexibly determined according to the size of the book and the specific size of the design. Although the function of waist seal for books can't be compared with the front cover, back cover and spine, it is also limited by area and the design space is relatively small.

Design the girdle according to the book title "Problems in Problems". Starting from the topic "problem", it caused confusion, and the word "problem in problem" was repeatedly designed into various fonts, changing the size and alluding to the meaning of the word "problem".

Modern book girdle design: girdle refers to a long and narrow strip around the waist of a set or a book or a stack of paintings. It is a form of loading some text, graphics and other information related to the book itself on the appearance of the book. Its length includes front cover, back cover, spine and front and rear cuffs, and its height is flexibly determined according to the size of the book and the specific size of the design.

Function of the girdle: The girdle and the envelope have basically the same function, both for better protection of books, but the advertising function of the girdle is more specific, and some important events related to books will be printed, such as book awards, sales performance, content introduction, etc.