In thermal printing ink, hydrophilic fumed silica speeds up the drying pace, it helps avoiding smudged and blurred products caused by wet ink; In normal printing ink, hydrophobic fumed silica limits ink to adsorb water and removes foam, the color intensity improved while ink surface still shines; In gravure printing, flexography printing and silk printing, fumed silica works as anti-settling agent, and it can control the ink volume while printer is working for clean and clear printing results; In cartridge for printers, fumed silica works as dispersion agent and volume control agent.