A curable formaldehyde-free resin in the form of an aqueous dispersion. The resin comprising components a), b) and c), wherein: a) is water-insoluble native starch, b) is a polycarboxylic polymer, and c) is non-polymeric polycarboxylic acid compound, and wherein the amount of polycarboxylic polymer (b) comprised in the resin is between 2 and 45 wt.-% relative to the sum of the weights of the components a), b) and c).