Erasable pen ink is a kind of color ink mainly made of water-soluble solvent, supplemented by polymer film forming agent, pigment and other additives. Writing tools composed of ink and matching pens and boards can be used in school teaching, office work, academic exchanges, children's painting and calligraphy exercises, etc. It is characterized by smooth writing, easy writing and erasing, and no dust pollution, and can completely replace chalk and blackboard. An electric company in Japan first studied this product, and then Ciba Jiaji Company in Switzerland specially developed a series of special pigments for this ink. Since then, this kind of pen and ink has been developed in many countries and attracted the attention of the world education community. Compared with traditional chalk, this product has remarkable economic and social benefits. The product meets the standard of Q/BMS0 1- 1996. It has been proved by users that it is an ideal product for teaching blackboard writing, a major innovation of traditional teaching tools and a new domestic product. YZ- 1 erasable ink production technology combines advanced pigment dispersion and stabilization technology. The application performance of ink produced by this production technology ranks at the advanced level of similar products in China, reaching or approaching the advanced level of foreign products, and its cost performance is higher than that of foreign products.