Ink is mainly used in printing industry. Pigment and binder are two main raw materials of ink. Ink is the material used to form graphic information in the printing process, so ink plays an important role in printing. It directly determines the image tone, color, clarity and so on. Pigment is the solid component of ink, which is the chromogenic substance of ink. It is generally insoluble in water. The saturation of ink color, printing ink power and transparency are closely related to the performance of pigment.