The invention provides a coating composition containing boehmite particles and a dispersant which comprises a compound having an anchoring moiety linked to a polymeric hydrophilic moiety, the anchoring moiety containing at least one acid and/or hydroxy group and having overall acidity or neutrality and the polymeric moiety having a lower affinity for a boehmite surface than the anchoring moiety. The anchoring moiety preferably contains at least two acid groups, preferably carboxylic acid groups, attached either in a [1,1], [1,2] or [1,3] relationship and is linked to the polymeric moiety, which is preferably derived from acrylamide or methacrylamide monomer units, preferably by a sulfur atom. The dispersant can reduce the viscosity of the boehmite dispersion and the tendency of the boehmite dispersion to increase in viscosity and/or form a gel or a yield stress material following periods of high shear stress.