A radiation-curable ink including, (a) a colorant dispersion containing a pigment and a diluent, the pigment being present in an amount of 20 to 95 weight % based on the total weight of the colorant dispersion; (b) polymerizable compound; and (c) a polymerization initiator, wherein the radiation-curable ink has a viscosity of 6 to 500 mPas measured at 25.degree. C. and comprises water in an amount of not more than 2.5 weight % based on the total weight of the radiation-curable ink measured with Karl Fisher method.