Reduce contact with air, reduce contact with moisture and reduce contact with sunlight.
For most people, contact with air is inevitable, but contact with moisture and sunlight can be avoided as much as possible. If you don't use some books often, you can try to seal them in plastic bags and take them out when you use them. Usually, the shelf life of paper should not exceed one year. Even if the storage conditions of paper are good, the paper will change color and deteriorate if it is stored for too long. If the paper is stored for two years, the coated paper will turn yellow and lose powder; Newsprint turns yellow and brittle; The wrapping paper is discolored and its strength is reduced; Yellow paperboard and box paperboard will go moldy and deteriorate, and so on.
Methods to prevent paper from yellowing;
1. Use it to glue people (there are several kinds of glue, also called polishing or oil painting).
2. Hot-pressed membrane shell protection;
3. Store in a professional safe;
4. Mounting, all kinds of materials are effective;
5. Press under the table glass or plastic mat.