Methods and compositions are provided for hardening with fast-acting hardeners the colloidal carrier materials, such as gelatin, in the layers of photographic materials, such as photographic film. The methods of the invention comprise coating, with a conventional coating technique, among the layers of a photographic material a layer of a composition of the invention. The compositions of the invention are aqueous solutions which comprise a fast-acting hardener and a polymeric thickener, have concentrations of thickener less than about 50 mg/cm.sup.3 and, at 40.degree. C. and shear rates between about 1000 sec.sup.-1 and 10,000 sec.sup.-1, have viscosities from about 5 cp to about 20 cp and power law indices greater than about 0.90.