like as necessary by a polymerization method such as emulsion polymerization solution polymerization bulk polymerization or the like one such resin or a combination of 2 or more such resins may be used as pigments titanium oxide carbon black red ocher and other coloring pigments baryta powder precipitated barium sulfate barium carbonate calcium carbonate calcium sulfate clay silica white carbon diatomaceous earth talc magnesium carbonate alumina white gloss white and other body pigments and various other pigments used conventionally in coating agents can be selected according to the desired color the content of the pigment in the coating material is preferably 0 1 to 5 mass or more preferably 0 5 to 3 mass if the content of the pigment is less than 0 1 mass sufficient coloration is not obtained while above 5 mass color irregularities are more likely the film forming aid is one that has a higher boiling point than water and can semi dissolve the resin particles with a higher boiling point than water the coating agent can maintain a fluid state even after the water evaporates and adhesion between resin particles is greater because they are semi dissolved resulting in a smoother coated film in the present invention n methyl pyrrolidone methyl.