A process for obtaining a water-borne non-biologically active crosslinkable composition comprising a block copolymer comprising at least blocks x y and a polymer P, the block copolymer - polymer composition having an acid value ≤ 150 mg KOH per g of block copolymer - polymer, where at least block and is obtained by a controlled radical polymerisation of at least one ethylenically unsaturated monomer via a reversible addition-fragmentation chain transfer (RAFT) mechanism in solution in the presence of a control agent and a source of free radicals; where block comprises: i) 0 to 50 mol% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 50 to 100 mol% ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 0 to 50 mol% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 35 mol% of ethylenically unsaturated monomers units different from those from i), ii) + iii); where i), ii), iii) + iv) add up to 100%; block has a Hansch parameter < 1.5 measured according to the specification's description; and block has an average degree of polymerisation x, where x is an integer from 3 to 80; where block comprises: i) 5 to 80 mol% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 20 mol% of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 20 to 95 mol% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 35 mol% of ethylenically unsaturated monomers units different from those from i), ii) + iii); where i), ii), iii) + iv) add up to 100%; block has a Hansch parameter ≥ 1.5 measured according to the specification's description; and block has an average degree of polymerisation y, where y is an integer ≥ 10, where y > x; and where the polymer P is obtained in the presence of the block copolymer by an emulsion polymerization process; and comprises: i) 0 to 5 wt% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 5 wt% of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 80 to 100 wt% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 10 wt% of ethylenically unsaturated monomers units different from those from i), ii) + iii); where i), ii), iii) + iv) add up to 100%. i) 0 to 50 mol% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 50 to 100 mol% ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 0 to 50 mol% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 35 mol% of ethylenically unsaturated monomers units different from those from i), ii) + iii); block has a Hansch parameter < 1.5 measured according to the specification's description; and block has an average degree of polymerisation x, where x is an integer from 3 to 80; i) 5 to 80 mol% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 20 mol% of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 20 to 95 mol% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 35 mol% of ethylenically unsaturated monomers units different from those from i), ii) + iii); where i), ii), iii) + iv) add up to 100%; block has a Hansch parameter ≥ 1.5 measured according to the specification's description; and block has an average degree of polymerisation y, where y is an integer ≥ 10, where y > x; and i) 0 to 5 wt% of ethylenically unsaturated monomer units bearing crosslinking functional groups; ii) 0 to 5 wt% of ethylenically unsaturated monomer units bearing water-dispersing functional groups; iii) 80 to 100 wt% of ethylenically unsaturated monomers units selected from C 1-18 alkyl(meth)acrylate monomers and styrenic monomers; iv) 0 to 10 wt% of ethylenically unsaturated monomers units different from those from i), ii) + iii);