However, the water-soluble thickener which includes, for example, a cellulose derivative such as hydroxylpropyl cellulose, carboxylmethyl cellulose, hydroxylethyl cellulose, methyl cellulose or the like, or polyvinyl alcohol tends to change a viscosity of the ink composition or, in some cases, to produce precipitates during storage in combination with a water-soluble dye or coloring agent.