How does the library preserve ancient books?

From my personal work experience, the biggest problem in the preservation of ancient books in China is paper and stains. The paper of ancient books in China often turns yellow and brittle due to acidification, and the stains are divided into mildew spots, oil stains, handprints, ink stains, fly stains and mosquito stains. Stains affect the original appearance of ancient books, and will have different diffusion effects with the temperature and humidity environment, which will also seriously affect the preservation of ancient books. When preserving ancient books in China, we must stay away from all western-style papers, because western-style papers are corrosive, especially during the Republic of China. At the same time, natural camphor, borneol, vanilla, rue, sandalwood and other Chinese herbal medicines and their preparations are placed in the bookcase to prevent insects, and chemical pesticides are strictly prohibited. Never repair ancient books with chemical glue, chemical paste or cellophane.