The present invention relates to a waterborne dispersion comprising (A) amphiphilic block copolymer obtained with a controlled radical polymerization process and comprising at least blocks [A] and [B], whereby block [A] comprises ethylenically unsaturated monomer(s) bearing water-soluble and/or water-dispersible functional groups (monomer(s) (i)), and block [B] comprises ethylenically unsaturated monomer(s) different from monomer(s) (i) (monomer(s) (ii)); and (B) polymer P comprising ethylenically unsaturated monomer(s) different from (i) (monomer(s) (ii)), characterized in that the amount of block copolymer is higher than 1 and lower than 30 wt. %, based on the total weight of monomers used to prepare the block copolymer and polymer P; the acid value of the composition consisting of block copolymer and polymer P is higher than 1 and at most 35 mg KOH per g of the block copolymer-polymer P composition; the block copolymer has a calculated glass transition temperature of higher than 10° C. and lower than 250° C.; and polymer P comprises at least 20 wt. % (relative to the total monomer composition to prepare the polymer P) of a polymer fraction with calculated glass transition temperature higher than 10° C. and lower than 100° C.