Recently, pigmented inks became popular for personal and office printers. They have advantages in waterfastness and lightfastness, but they have limitations on clear color, rub resistance and jetting reliability. Therefore, new inks have been required to overcome these problems.We have developed new emulsion colorant in order to solve these problems. The colorant is water based polymer emulsion containing water insoluble dye. The emulsion colorant based inks show clear color, rub resistance like water soluble dye based inks and waterfastness, sharpness like pigmented inks. But the emulsion colorant based inks cause clogging at the nozzle of print head, and by this clogging jetting reliability are fallen off.To solve this problem, we investigated various humectants suitted to the emulsion colorant. As the result, we found that addition of glycine derivatives improved jetting reliability of the emulsion colorant based inks sharply, and that glycine derivatives were useful humectant for pigmented inks, too.