Why is it taboo to practice calligraphy?

Because we don't use ink and rice paper, writing on water book cloth has no ink resistance, and the written calligraphy works can't be preserved as long as writing on rice paper with ink.

Water-writing cloth is made according to the principle that pigment is transparent when it meets water. Generally speaking, water-writing cloth is made of black flannel with a layer of environmentally friendly white paint on the surface. This kind of paint has a special function, that is, it becomes 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 water is mainly due to the reflection of light.