1. Eraser cleaning. Use an eraser to remove stains from paper. Many dirty things stuck to books can be wiped off with an eraser.

2. Alcohol decontamination. Spray a proper amount of alcohol on the front and back of the book, and then wipe it with a rag to remove the stains that the eraser can't erase. At the same time, alcohol also has the function of disinfection.

3. Sandpaper grinding. Sandpaper can remove stubborn stains that neither eraser nor alcohol can remove, and at the same time, it can polish yellow edges.

4. Product classification. When decorating, the products are divided into three categories: brand-new, first-class and medium-class, among which "brand-new, first-class" has no more detailed description, while "medium" contains more detailed descriptions such as "slight wear, stains, yellowing, mildew, breakage, remarks and creases".

5. Ozone disinfection. You can buy a book sterilizer: a book file sterilizer. Every book must be disinfected with ozone for one hour.

6. Plastic packaging again. Compound plastic packaging can isolate the dust, stains and strong light of books, and can also prevent extrusion deformation during sorting and transportation.