The invention refers to a coating composition which, calculated on dry weight, is comprising at least 20 % by weight polyvinyl alcohol and 0.1 to 20 % by weight, calculated on the weight of the polyvinyl alcohol, of a water-insoluble (meth)acrylate copolymer comprising quaternary ammonium groups, wherein the viscosity of an aqueous dispersion comprising that coating composition with 25 % (w/w) solid content at 22 °C is 200 mPa.s or less.
