Patent ID: 8734919

Claim:
A pre-stressed substrate for a photographic paper comprising: (a) a base paper having a front surface and a back surface, (b) a top pre-stress coat on said front surface, said top pre-stress coat comprising a first pre-stress mixture containing at least a first pigment, a first binding material (TBM 1 ) comprising a first water soluble binder (WSB 1 ) and a first water-dispersible binder (WDB 1 ); (c) a back pre-stress coat on said back surface, said back pre-stress coating comprising a second pre-stress mixture containing at least a second pigment, a second binding material (TBM 2 ) comprising a second water soluble binder (WSB 2 ) and, optionally, a second water dispersible binder (WDB 2 ), wherein the weight % of WSB 1 in the TBM 1 is less than the weight % of WSB 2 in the TBM 2 ; (d) a first polymeric film layer on said top pre-stress coat; and (e) a second polymeric film layer on said back pre-stress coat, wherein said pre-stressed substrate has a predetermined degree of curvature toward the back surface and is capable of countering curling forces that occur during image receiving layer coating and final product use.