Abstract: Aqueous coating compositions comprise a polymer of defined molecular weight which contains either anionizable or cationizable groups and also certain defined non-ionizable water-soluble moieties (derived for example from polyethylene glycol), water, optionally an organic coupling solvent and optionally either base or acid. The presence of regularly distributed non-ionizable water-soluble moieties enables the selection of aqueous polymer solutions which, on dilution, show a regular relationship between viscosity and solids content. The polymer solutions are useful in the formulation of coating compositions, particularly paints.