Method for stabilizing the image of a thermally developable photosensitive material

In a method for forming an image in a thermally developable photosensitive material which comprises imagewise exposing a thermally developable photosensitive material comprising a support having thereon a layer containing at least (a) an organic silver salt;

• (b) a catalytic amount of a photosensitive silver halide or a compound capable of forming a silver halide upon reaction with the organic silver salt (a);
• (c) a reducing agent and (d) a binder and heating the thermally developable photosensitive material, the improvement which comprises stabilizing the image formed by contacting the photosensitive layer of the photosensitive material during or after the heating with a polymer film layer containing a compound represented by the following general formula
• X C -- SH or X C = S
• in which X represents the non-metallic atoms necessary for forming a 5- or 6-membered heterocyclic ring containing at least one of a nitrogen, oxygen or sulfur hetero atom, said compound of the general formula being present in an amount sufficient to stabilize said image.