Basic principle: when writing with clear water, the handwriting will turn black immediately, and it will return to red and green after drying, which can be used for 10 thousand writing exercises. It is a good practice carrier for painting and calligraphy lovers, and it can also help children learn painting and calligraphy and avoid the trouble of dirty clothes and black ink. It is a new environmental protection technology product. Water writing paper is the most advanced and popular durable paper in China. After a special process, water is used instead of ink. You can practice calligraphy and painting repeatedly with a brush or soft pen dipped in water. Writing paper with water has the advantages of practicality, convenience, repeated practice, cleanliness and hygiene, and replacing ink with water. Keep the handwriting for about 5 minutes, and then use it after drying. Each piece of paper can be reused thousands of times. Especially suitable for primary and secondary school students and calligraphy lovers to practice.