An aqueous dispersion of polyurethane-addition polymer hybrid particles, where the isocyanates used to make the polyurethane polymer portion of the particles comprise a mixture of aromatic polyisocyanate and aliphatic polyisocyanate wherein the aromatic isocyanate is free of sterically hindered isocyanate moieties. The dispersions are suitable for use in coatings, including varnishes, paints, inks and adhesives.