(1) The mildew spots on books can be wiped with alum solution, and then covered with absorbent paper to absorb water.

② Mild and repeated wiping with ammonia water can also remove mildew spots.

Anti-mildew method of stamps (universal edition)

Mild mildew, first dry in dry weather, and then gently wipe off the mildew on the stamp with a new brush. If there are still mildew spots, you can gently wipe them off with clean high-grade drawing glue. If the mildew spots are serious, you can cook some fresh milk (not washed with milk powder) and add some refined salt. When the salt is dissolved and the milk is cooled, immerse the stamp in the milk, preferably hold it down with a hard object and let it soak. 1 ~ 2 hours later, take it out, then gently wipe the mildew spots on the stamp with a new brush or cotton wool, rinse it with clear water several times, and flatten it with absorbent paper.

(Supplementary) Anti-mildew Methods for Calligraphy and Painting

Take the same amount of camphor and borneol, dissolve them in 75% alcohol, soak the paper with strong water absorption for 2 ~ 3 minutes, dry it in the shade, and put it in calligraphy and painting to prevent mildew.