Like the composition of general printing inks, water-based inks usually also have colorants, binders, auxiliary agents and other components. Colorants are the coloring substances of water-based inks, which give the ink a specific color. In flexo printing, in order to make the imprint colorful, the colorant is generally selected from pigments with good chemical stability and high tinting strength; the binder is composed of water, resin, amine compounds and other organic solvents. Resin is the most important component in water-based inks. Water-soluble acrylic resins are usually used. The binder component directly affects the adhesion function, drying speed, and anti-fouling performance of the ink. It also affects the gloss and ink transfer of the ink. The main amine compounds Maintain the alkaline pH value of the water-based ink, so that the acrylic resin can provide better printing effect. Water or other organic solvents mainly dissolve the resin and adjust the viscosity and drying speed of the ink. The auxiliary agents mainly include: defoamer, retarder , stabilizer, diluent and so on. Since the water-based ink is a soap composition, it is easy to generate air bubbles during use, so silicone oil should be added as a defoaming agent to suppress and eliminate air bubbles, and at the same time improve the transfer performance of the ink. The retarder is used to inhibit the drying speed of the water-based ink, prevent the ink from drying on the anilox roller, and reduce the paste. The stabilizer can adjust the PH value of the ink, and can also be used as a diluent to reduce the viscosity of the ink. Diluent is used to reduce the color of water-based ink, and can also be used as a brightener to improve the brightness of water-based ink. In addition, some waxes should be added to the water-based ink to increase its wear resistance.