Photographic plate

Claim 1

A PHOTOGRAPHIC PLATE COMPRISING AN ALUMINUM SHEET WHICH HAS BEEN TREADED TO PRODUCE AN ARTIFICIAL POROUS ALUMINUM OXIDE COATING THEREON, AND WHICH HAS NOT BEEN COMPLETELY SEALED SO THAT IT RETAINS RESIDUAL POROSITY, A SUBSTRATE MATERIAL IN THE PORES OF SAID COATING ONLY PARTIALLY FILLING THE PORES AND LEAVING SPACES IN SAID PORES, SAID FILLER MATERIAL HAVING HYDROPHILIC AND ORGANOPHOBIC PROPERTIES, AND A WATER-INSOLUBLE, IMAGE-DEFINING LAYER OVER SAID PORE-FILLED ALUMINUM OXIDE COATING HAVING THE PROPERTIES OF BEING WATER-INSOLUBLE, HYDROPHOBIC AND ORGANOPHILIC, SAID ALUMINUM OXIDE COATING CONTAINING SAID SUBSTRATE MATERIAL BEING EXPOSED IN THE NON-IMAGE AREAS OF THE PLATE BETWEEN THE AREAS OF THE IMAGE-DEFINING COATING, SAID SUBSTRATE BEING OF SUCH THICKNESS AND IN SUCH FORM AS TO PERMIT THE IMAGE-DEFINING LAYER TO REACH INTO SAID SPACES FOR ANCHORAGE THEREBY.