Process for making color separation negatives and positives for use in multi-color printing

Claim 1

A method of manufacturing intermediate and final color-separation negatives and positives from a color original suitable for use in screenless printing, comprising the steps of: exposing a continuous-tone panchromatic (pan) film including a silver halide emulsion through a selected filter to light from said color original and developing said film to a density not exceeding 1.0, said developed pan film being termed an intermediate color-separation negative, said development of said pan film being effected under conditions such as to produce silver crystals larger in size than produced in normal development, said conditions including at least one of the steps, (A) raising the temperature of the developer from its normal temperature by up to about 10° C., (B) increasing the time of rinsing by a factor of up to about 6, and (C) increasing the drying temperature up to a maximum of about 40° C. with the objective of increasing the size of the silver crystals formed in said development of said film; placing said intermediate color-separation negative in contact with an orthochromatic continuous-tone film and exposing and developing said orthochromatic film to prepare a first grey mask having a density range of 40-80% of the density range of said intermediate negative; exposing, and subsequently developing, a first lithographic (lith) orthochromatic film in a stack arranged as follows, the components in said stack being listed in order from the light source: (a) a first diffusion film having one matte surface and said matte surface facing toward said light source; (b) said first grey mask with the emulsion layer thereof facing toward said light source; (c) said intermediate color-separation negative with the emulsion layer thereof facing away from said light source; and (d) said first lith film with the emulsion side thereof facing toward said light source, said exposed and developed first lith film being an intermediate positive; preparing a second grey mask by exposing an orthochromatic continuous-tone film through said intermediate positive and developing same to a density range of 30-40% of that of said intermediate positive; preparing a second stack, the components of said stack being listed in order from a light source; (e) said second grey mask with the emulsion side thereof facing toward said light source; (f) said intermediate positive with the emulsion side thereof facing away from said light source; and (g) a second lith orthochromatic film with the emulsion side thereof facing toward said light source; exposing said stack for 85-90% of the necessary time; removing said second grey mask from said second stack; exposing said stack for the remaining 10-15% of the necessary time; and completing the developing of said second lith film to produce a final negative, the term "developing" being taken to include actual developing, fixing, rinsing and drying.

Claim 2

A method of manufacturing intermediate and final color-separation negatives and positives from a color original suitable for use in screenless printing, comprising the steps of: exposing a continuous-tone panchromatic (pan) film including a silver halide emulsion through a selected filter to light from said color original and developing said film to a density not exceeding 1.0, said developed pan film being termed an intermediate color-separation negative, said development of said pan film being effected under conditions such as to produce silver crystals larger in size than produced in normal development, said conditions including at least one of the steps, (A) raising the temperature of the developer from its normal temperature by up to about 10° C., (B) increasing the time of rinsing by a factor of up to about 6, and (C) increasing the drying temperature up to a maximum of about 40° C. with the objective of increasing the size of the silver crystals formed in said development of said film; placing said intermediate color-separation negative in contact with an orthochromatic continuous-tone film and exposing and developing said orthochromatic film to prepare a first grey mask having a density range of 40-80% of the density range of said intermediate negative; exposing, and subsequently developing, a first lithographic (lith) orthochromatic film in a stack arranged as follows, the components in said stack being listed in order from the light source: (a) a first diffusion film having one matte surface and said matte surface facing toward said light source; (b) said first grey mask with the emulsion layer thereof facing toward said light source; (c) said intermediate color-separation negative with the emulsion layer thereof facing away from said light source; and (d) said first lith film with the emulsion side thereof facing toward said light source, said exposed and developed first lith film being an intermediate positive; preparing a second grey mask by exposing an orthochromatic continuous-tone film through said intermediate positive and developing same to a density range of 30-40% of that of said intermediate positive; preparing a second stack, the components of said stack being listed in order from a light source; (e) said second grey mask with the emulsion side thereof facing toward said light source; (f) said intermediate positive with the emulsion side thereof facing away from said light source; and (g) a second lith orthochromatic film with the emulsion side thereof facing toward said light source; exposing said stack for 85-90% of the necessary time; removing said second grey mask from said second stack; exposing said stack for the remaining 10-15% of the necessary time; and completing the developing of said second lith film to produce a final negative, the term "developing" being taken to include actual developing, fixing, rinsing and drying.

Claim 4

The method as defined in claims 1 or 2, wherein said process is carried out so that said intermediate color separation negative has a density range not exceeding 0.8.

Claim 5

The method as defined in claims 1 or 2, including the steps of preparing the four intermediate color-separation negatives, yellow with a density range of about 0.67, red with a density range of about 0.78, blue with a density range of about 0.76, and black with a density range of about 0.74.

Claim 6

The method as defined in claims 1 or 2, wherein the development of said first grey mask includes the substeps, subsequent to exposure, of thoroughly soaking said first grey mask film in pure water; developing said film with continuous-agitation for 1 to 3 minutes in a developer of at least normal softness, i.e., no harder than normal hardness; stopping the development of said film in a stop bath; fixing said film with agitation for at least the first few seconds; and rinsing said film in water and drying same in a drying cabinet.

Claim 9

A method of manufacturing from a color original a duplication negative suitable for use in screenless color printing, comprising the steps of: exposing a panchromatic (pan) continuous-tone film having a silver halide emulsion through a selected filter to light from said color original, and subsequently developing and drying said film, thereby producing an intermediate color-separation negative, said exposure, development and drying being carried out under conditions such that said intermediate negative has a density range not exceeding 1.0, and the silver grains produced are larger than produced under normal development and drying; preparing on an orthochromatic continuous-tone film a grey mask from said intermediate negative by exposure in contact therewith and subsequent development under conditions such that said grey mask has a density range of 40-80% of that of said intermediate negative; and exposing, and subsequently developing, a negative duplication film in a stack arranged as follows, the components in said stack being listed in order from the light source: (a) a light-diffusion film having one matte surface, said matte surface facing toward said light source; (b) said grey mask with its emulsion layer facing said light source; (c) said intermediate color-separation negative with its emulsion layer facing away from said light source; (d) said duplication film with its emulsion layer facing said light source; said exposed and developed duplication film being said duplication negative.

Claim 10

A method of manufacturing from a color original a duplication negative suitable for use in screenless color printing, comprising the steps of: exposing a panchromatic (pan) continuous-tone film having a silver halide emulsion through a selected filter to light from said color original, and subsequently developing and drying said film, thereby producing an intermediate color-separation negative, said exposure, development and drying being carried out under conditions such that said intermediate negative has a density range not exceeding 1.0, and the silver grains produced are larger than produced under normal development and drying; preparing on an orthochromatic continuous-tone film a grey mask from said intermediate negative by exposure in contact therewith and subsequent development under conditions such that said grey mask has a density range of 40-80% of that of said intermediate negative; and exposing, and subsequently developing, a negative duplication film in a stack arranged as follows, the components in said stack being listed in order from the light source: (a) a light-diffusion film having one matte surface, said matte surface facing toward said light source; (b) said grey mask with its emulsion layer facing said light source; (c) said intermediate color-separation negative with its emulsion layer facing away from said light source; (d) said duplication film with its emulsion layer facing said light source; said exposed and developed duplication film being said duplication negative.

Claim 12

The method as defined in claims 8 or 9, further comprising the step of preparing from said duplication negative a positive on lith orthochromatic film.

Claim 13

The method as defined in claims 8 or 9, further comprising the steps of preparing from said duplication negative on orthochromatic continuous-tone film by contact with said duplication negative a second grey mask of limited density range, assembling a stack for exposure to a light source, the components in said stack being as listed in order from the light source: (f) said second grey mask with the emulsion side thereof facing toward said light source; (g) said duplication negative with its emulsion side facing away from said light source; and (h) a lithographic (lith) orthochromatic film with its emulsion layer facing toward said light source; and exposing and developing said lith film color thereby forming a final positive useful for multi-color printing.

Claim 15

The method as defined in claims 11 or 12, wherein the development of said second grey mask comprises the substeps of thoroughly soaking the exposed second grey mask film in pure water, placing the exposed mask film in a developer at least as soft as normal liquid developer and agitating continuously for 1-3 minutes, transferring same promptly to a stop bath for a few seconds, transferring to a fixing bath with agitation for the first few seconds in said bath, rinsing in water and drying in a drying cabinet.