What is the alum water of Chinese landscape painting and ice and snow landscape painting?

Alum water is an aqueous solution in which alum is dissolved.

It is a colorless and translucent crystal. Alum plays an isolation role in painting, and "three alum and nine dyes" means fixing color with alum. Pay attention to the dosage when using alum, because alum is very destructive to paper and will be corroded, which will affect long-term preservation, so it is called "paper biting".

In the production of glue alum water, the proportion of glue alum is generally "two glues, one alum, two catties and half water", that is, 60g gelatin+30g alum+1250g water. This ratio should be appropriately adjusted according to the cold weather and sunny days, and the configuration of "six glues and four aluminum in summer, eight glues and two aluminum in winter and three aluminum and seven glues in winter" should be flexibly mastered.