A composition comprising (i) a non-ionic surfactant R 1 -O-A-O-R 2, wherein - the residue -O-A-O- is derived from a polyalkylene glycol HO-A-OH that comprises 2-130 monomer units derived from ethylene glycol and 0-60 monomer units derived from propylene glycol; and - R 1 is selected from the group consisting of -H, -(C 8 -C 20)-alkyl, -(C 8 -C 20)-alkenyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl, and - R 2 is selected from the group consisting of -H, -(C 1 -C 6)-alkyl, -benzyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl; and (ii) a water-soluble ionic polymer, wherein the water-soluble ionic polymer is derived from a monomer composition containing a) one or more non-ionic ethylenically unsaturated monomers, and/or b) one or more cationic ethylenically unsaturated monomers, and/or c) one or more anionic ethylenically unsaturated monomers; and wherein the water-soluble ionic polymer is derived from a monomer composition (i) not comprising any cross-linking monomers, or (ii) containing not more than 50 ppm cross-linking monomers, relative to the total content of monomers in the monomer composition; wherein the non-ionic surfactant R 1 -O-A-O-R 2 is present in an amount of from 0.05 wt.-% to 2.0 wt.-%, based on the total weight of the composition; and wherein the relative weight ratio of the non-ionic surfactant R 1 -O-A-O-R 2 to the ionic polymer is within the range of from 0.05: 100 to 2: 100. (i) a non-ionic surfactant R 1 -O-A-O-R 2, wherein - the residue -O-A-O- is derived from a polyalkylene glycol HO-A-OH that comprises 2-130 monomer units derived from ethylene glycol and 0-60 monomer units derived from propylene glycol; and - R 1 is selected from the group consisting of -H, -(C 8 -C 20)-alkyl, -(C 8 -C 20)-alkenyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl, and - R 2 is selected from the group consisting of -H, -(C 1 -C 6)-alkyl, -benzyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl; and - the residue -O-A-O- is derived from a polyalkylene glycol HO-A-OH that comprises 2-130 monomer units derived from ethylene glycol and 0-60 monomer units derived from propylene glycol; and - R 1 is selected from the group consisting of -H, -(C 8 -C 20)-alkyl, -(C 8 -C 20)-alkenyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl, and - R 2 is selected from the group consisting of -H, -(C 1 -C 6)-alkyl, -benzyl, -(C=O)-(C 8 -C 20)-alkyl and -(C=O)-(C 8 -C 20)-alkenyl; and (ii) a water-soluble ionic polymer, wherein the water-soluble ionic polymer is derived from a monomer composition containing a) one or more non-ionic ethylenically unsaturated monomers, and/or b) one or more cationic ethylenically unsaturated monomers, and/or c) one or more anionic ethylenically unsaturated monomers; and wherein the water-soluble ionic polymer is derived from a monomer composition (i) not comprising any cross-linking monomers, or (ii) containing not more than 50 ppm cross-linking monomers, relative to the total content of monomers in the monomer composition; a) one or more non-ionic ethylenically unsaturated monomers, and/or b) one or more cationic ethylenically unsaturated monomers, and/or c) one or more anionic ethylenically unsaturated monomers; and (i) not comprising any cross-linking monomers, or (ii) containing not more than 50 ppm cross-linking monomers, relative to the total content of monomers in the monomer composition;