Shuishu cloth is a kind of calligraphy and painting art supplies that can be used to practice calligraphy and painting with a brush after writing on its surface with clear water, and can be rewritten after drying. Water writing cloth is mainly made of cloth; According to the principle that coatings are transparent when exposed to water; With black cloth as the medium, the surface is coated with a layer of environmentally-friendly white paint treated by special technology, which has the effect of being transparent when it meets water. The main component of paint is silicon dioxide, which is the main component of sand and the main raw material for making water cups. Transparency in contact with water is mainly the physical principle of light reflection.