PAPEL-SW VARIABLE DE GRADACION

UN PAPEL -SW VARIABLE DE GRADACION CON SOLO UNA CAPA DE EMULSION DE HALOGENID DE PLATA, DONDE SE EVITA LA SENSIBILIZACION DE ULTERIOS SE MANTIENE UNA UNION DE LA FORMULA (FORMULA) CON UNA MEZCLA DE AL MENOS DOS EMULSIONES DE HALOGENID DE PLATA FOTOSENSIBILIZADAS, DE CUAL UNA TIENE SU MAXIMO DE ABSORCION EN EL MARGEN DE 480 A 580 NM. Y LA OTRA BAJO DE 480 NM., DONDE X REPRESENTA LAS ARTICULACIONES RESIDUALES DE UN HETEROCICLO BENZO O NAFTOCONDENSADO, QUE CONTIENE EN EL CASO DADO OTROS CONSTITUYENTES. A gradation-variable BW paper comprising only one silver halide emulsion layer, in which re-sensitization is avoided, is obtained with a mixture of at least two photosensitive silver halide emulsions, of which one has its absorption maximum in the range from 480 to 580 while the other has its absorption maximum below 480 nm, providing the emulsion which has its absorption maximum below 480 nm contains a compound corresponding to the following formula in which X represents the remaining members of an optionally benzo- or naphtho-condensed heterocycle optionally containing further substituents.