Photographic diffusion transfer colour film unit

A photographic film unit comprises a photosensitive laminate containing a dimensionally stable transparent support carrying, on one surface, a processing compsn. permeable, dyeable polymeric layer, a processing compsn. permeable opaque layer and a photosensitive silver halide layer having associated dye image-forming material, pref. a dye-developer, which is processing compsn. diffusible, as a function of the emulsion's exposure to actinic radiation. The film may be maintained integral subsequent to processing, and during processing the transfer image formation may be viewed through the transparent support when a dimensionally stable sheet adapted to be superposed during processing over the laminate opposite the transparent support is present and is opaque, thus preventing further exposure of the photosensitive layer(s). The film unit pref. contains an acidic polymeric layer and have attached a rupturable container retaining a processing compsn.