Backing materials mainly include the following parts:
First, the book back with cloth
The commonly used book back is gauze. It is a woven loose-grain cotton fabric that is easy to penetrate the glue and stiffens after sizing. Placing the gauze on the back of the book block can improve the flatness of the back of the book and the bond fastness between the books, which is beneficial to the shaping of the back of the book. Hardcover books must be book-backed. For thicker paperback books, book backs are added to increase the back-to-back adhesion or lock fastness.
Second, the book back paper
The back of the book is a backing paper stuck to the back of the book block to reinforce the back of the book.
For paperback books, when the thickness of the book block is more than 15mm, the backing paper must be attached. The amount of backing paper that is commonly used on a perfect binding line is 150 to 250 g/m2 offset paper or paperboard. Before use, rewind the web to the desired width based on the length of the back of the book.
For hardcover books, kraft paper with good strength and flexibility should be used as backing paper and cheese paper.
Third, plug cloth
Plug cloth cotton fabric belt. With a raised ridge, there is a single color and a color. Stick on the back of the book to increase the bond fastness of the signatures and beautify the books. The width of the plug cloth is generally 15mm.
Fourth, ribbon
Ribbon, also known as the ribbon, is a 5- to 8-mm wide silk ribbon with red, green, yellow and other colors. The ribbon is glued in the middle of the back of the book, and the growth section is sandwiched in the book block and exposed under the foot.