US2914406A

US2914406A - Method of gravure reproduction

Info

Publication number: US2914406A
Application number: US524459A
Authority: US
Inventors: John G Consaul; Velten Edwin
Original assignee: Art Color Printing Co
Current assignee: Art Color Printing Co
Priority date: 1955-07-26
Filing date: 1955-07-26
Publication date: 1959-11-24
Anticipated expiration: 1976-11-24

Description

Nov. 24, 1959 J. G. CONSAUL ET AL MEII'I-IOD 0F GRAVURE REPRODUCTION Filed July 26, 1955 STEPI MAKE A CONTINUOUS-TONE NEGATIVE FROM COPY TO BE REPRODUCED MAKE A CONTINUOUS-TONE POSITIVE STEP2 FROM THE CONTINUOUS-TONE NEGATNE OF STEP I STEP 3 MAKE PHOTOGRAPHICALLY A LINE SCREEN NEGATIVE DIRECTLY ON A LIGHT SENSITIVE RESIST FROM THE CONTINUOUS- TONE POSITIVE OF STEP 2 STEPS TRANSFER RESIST TO COPPER CYLINDER OR PLATE, DEVELOP AND ETCH IN THE USUAL WAY INVENTORS. JOHN G. CONSAUL EDWIN VEL-T EN BY A ATTORNEY United States Patent M rmrnon 0F GRAVURE REPRODUCTION John G. Consaul, Bayonne, and Edwin Velten, Gladstone, N.J., assignors to Art Color Printing Company, New York, N.\. and Dunellen, N.J., a corporation of New York Application July 26, 1955, Serial No. 524,459

3 Claims. (Cl. 96-38) This invention relates to a method of gravure reproduction, and more particularly to certain improvements in the method disclosed in our copending application, Serial No. 524,458 filed on July 26, 1955, and entitled Method of Gravure Reproduction.

The primary object of the present invention is to simplify the method of said copending application by omitting certain steps thereof. The instant method eliminates the necessity of making screened negatives and positives as in the former case. According to the present method a line screen negative and an unlined or unscreened negative are formed successively on a light sensitive resist directly from a continuous-tone positive that has a photographic image thereon of the copy or subject to be reproduced.

Another object is to provide an improved method that avoids the form'mounting heretofore required to register two exposures on a carbon-tissue in the practice of the prior methods. Form mounting is a time consuming operation that requires a high degree of skill. The present method, while preserving the advantages of our former method with respect to increased tonal range, by eliminating form mounting effects a marked economy in time and labor. It also obviates printing on a carbontissue.

Other objects and advantages will appear from following description of the invention, reference being had to the accompanying drawing which illustrates a flow sheet on which the steps of the method are designated.

By the term line screen negative used in the specification and claims is the negative that results from simultaneous exposure through both a half-tone screen, and an auxiliary screening device. The term auxiliary screening device as used hereinafter and in the claims means a screening device of the kind described in our Patent No. 2,703,281 of March 1, 1955.

The first step in the practice of the present method is to make a continuous-tone negative of the copy or subject to be reproduced. A continuous-tone positive is then made from this negative in the usual way. Both the continuous-tone negative and the continuous-tone positive may be retouched as required. In the case of multicolor work the usual color separation negatives and positives are made. No invention or novelty is claimed as to these steps in themselves.

The following two steps, designated as

steps

3 and 4 on the drawing, distinguish our method from all prior art gravure reproduction methods of which we are aware. According to step 3 a line screen negative is made photographically from the continuous-tone positive of step 2 directly on a resist of a light sensitive silver emulsion film or the like. In making the line screen nega- 2,914,406 Patented Nov. 24, 1959 tive, the resist is exposed through both a half-tone screen and an auxiliary screening device that comprises a disk or stop having a plurality of circular openings arranged in two straight lines that cross each other at a right angle, which openings are centered with respect to the squares or reticulations of the half-tone screen. This results in forming on the resist a dotted image of the copy.

In step 4 of the method an unlined or unscreened negative is made on the same resist from the continuous-tone positive. In carrying out this step, the half-tone screen and the auxiliary screening device are removed from the camera and the resist is re-exposed to the continuoustone positive to form an image thereof directly upon the line screen image previously formed on said resist.

As the final step of the method the resist is transferred to the surface of the printing cylinder or plate, and the surface is then developed and etched in the usual way.

What we claim is:

1. The method of gravure reproduction which comprises making a continuous-tone negative from the copy to be reproduced, making a continuous-tone, unscreened positive from said negative, making a line screen negative of said continuous-tone positive on a light sensitive resist by exposing the resist photographically to said positive simultaneously through a half-tone screen and an auxiliary screening device comprising an opaque member having a plurality of spaced circular openings therethrough arranged in two straight lines that cross each other at a right angle and are centered with respect to squares of the half-tone screen, re-exposing the resist to said continuous-tone positive with said screens removed to make an unlined image thereof directly upon the line screen image formed on said resist, and transferring the resist to the printing surface, developing and etching said surface.

2. In a method of gravure reproduction the steps which consist in making a continuous-tone, unscreened positive of the copy to be reproduced, making a line screen negative directly on a light sensitive resist from said continuous-tone positive by exposing the resist photographically to said positive simultaneously through a half-tone screen and an auxiliary screening device comprising an opaque member having a plurality of spaced circular openings therethrough arranged in two straight lines that cross each other at a right angle and are centered with respect to squares of the half-tone screen, and re-exposing the resist to said continuous-tone positive with said screens removed to make an unlined image directly upon the line screen image formed on said resist.

3. The method of making an intaglio gravure printing plate or cylinder which comprises making a continuoustone positive of the copy to be reproduced, making a line screen negative of said continuous-tone positive on a light sensitive resist by exposing the resist photographically to said positive simultaneously through a half-tone screen and an auxiliary screening device comprising an opaque member having a plurality of spaced circular openings therethrough arranged in two straight lines that cross each other at a right angle and are centered with respect to squares of the half-tone screen, re-exposing the resist to said continuous-tone positive with said screens removed to make an unlined image thereof directly upon the line screen image formedon said resist, and transferring the resist to the printing surface of said plate or cylinder, developing and etching said surface.

References Cited in the file of this patent UNITED STATES PATENTS 2,040,247 Dultgen May 12, 1936 2,060,640 Shaw Nov. 10, 1936 2,096,794 Dultgen Oct. 26, 1937 4 2,182,559 Henderson Dec. 5, 1939 2,703,281 Consaul et a1 Mar. 1, 1955 2,731,346 Gresham Jan. 17, 1956 FOREIGN PATENTS 128,926 Australia Aug. 27, 1948 OTHER REFERENCES Cartwright et al.: Rotogravure, McKay Pub. Co. Inc., Lyndon, Kentucky, 1956.

Claims

1. THE METHOD OF GRAVURE REPRODUCTION WHICH COMPRISES MAKING A CONTINOUS-TONE NEGATIVE FROM THE COPY TO BE REPRODUCED, MAKING A CONTINUOUS-TONE, UNSCREENED POSITIVE FROM SAID NEGATIVE, MAKING A LINE SCREEN NEGATIVE OF SAID CONTINUOUS-TONE POSITIVE ON A LIGHT SENSITIVE RESIST BY EXPOSING THE RESIST PHOTOGRAPHICALLY TO SAID POSITIVE SIMULTANEOUSLY THROUGH A HALF-TONE SCREEN AND AN AUXILIARY SCREENING DEVICE COMPRISING AN OPAQUE MEMBER HAVING A PLURALITY OF SPACED CIRCULAR OPENING THERETHROUGH ARRANGED IN TWO STRAIGHT LINES THAT CROSS EACH OTHER AT A RIGHT ANGLE AND ARE CENTERED WITH RESPECT TO SQUARES OF THE HALF-TONE SCREEN, RE-EXPOSING THE RESIST TO SAID CONTINUOUS-TONE POSITIVE WITH SAID SCREENS REMOVED TO MAKE AN UNLINED IMAGE THEREOF DIRECTLY UPON THE LINE SCREEN IMAGE FORMED ON SAID RESIST, AND TRANSFERRING THE RESIST TO THE PRINTING SURFACE, DEVELOPING AND ETCHING SAID SURFACE.