JPH05262025A - Screen-less print and manufacture thereof - Google Patents

Abstract

PURPOSE:To manufacture a screen-less print capable of producing accurate stable divided form plates of each gradation at a film stage. CONSTITUTION:When a continuos toning separation film is contact-exposed and developed to a form plate material for lithoraphy and a screen-less print is manufactured by using the form plate, the continuous toning separation film is prepared in such a manner that special gradation divided for a highlight tone, a middle tone and a shadow tone and reproduced is set to a color scanner by employing the color scanner for electronic color separation, and color- separated. Consequently, the continuous toning separation film prepared is contact-exposed and developed to a form plate material for lithography and a machine plate is manufactured, and repeated printing is conducted by printing ink toned for each gradation by using said machine plate. Accordingly, the screen-less print capable of reproducing the full tone of an original is obtained.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screenless (meshless) printing plate used for a reproduction printing technique such as a painting, a printing method, and the printed product.

[0002]

2. Description of the Related Art As a method of reproducing a painting such as a watercolor painting by a printing technique, a color film original obtained by photographing an actual object is color-separated into four colors of yellow, magenta, cyan, and black by a color scanner, or When the color tone and gradation cannot be expressed with only four colors, a special color plate printed with special color ink may be added, but it is called a halftone dot in offset printing or primary color plate printing, and a halftone dot or cell in gravure printing. However, in any case, the gradation and color tone are reproduced with a set of small dots. For this reason, there is a limit in reproducing the subtle touches, textures, and gradations of the original, and when the printed matter is viewed with a magnifying glass such as a magnifying glass, halftone dots are visible and it is obvious that the printed matter is a printed matter.

There is a lithograph as a printing method without halftone dots. To make a lithograph plate, a technician called an artist creates a plate while comparing it with a manuscript and extracting colors. For this reason, the number of plates for printing (for printing) is as large as several tens, which requires skill and a lot of time for manual processing, resulting in high cost.

Therefore, in Japanese Patent Laid-Open No. 3-207687, in the process of printing a continuous tone color separation film on a plate material for lithographic printing, the gradations of highlight tone, middle tone and shadow tone of the original are set. In order to reproduce, we made a color separation that reproduces the gradation of only highlight, middle and shadow parts by changing the exposure amount,
Disclosed is a method for producing a screenless printed matter in which a planographic ink and a medium are mixed and diluted to perform overprinting with a printing ink corresponding to each tone.

However, according to the method of the above-mentioned publication, since a normal continuous color separation film is used and the separation amount of each gradation is produced by changing the exposure amount, it is difficult to produce it stably and accurately. There was a problem.

[0006]

DISCLOSURE OF THE INVENTION The present invention relates to a method for producing a screenless printed matter, which is capable of producing a stable and accurate gradation separation at a film stage, and a method for producing the same. It is an object to provide a screen-printed product.

[0007]

The present invention relates to a method for producing a screenless printed matter by subjecting a continuous toning separation film to a plate material for lithographic printing by contact exposure and development, and using the plate material, The toning separation film is divided into highlight tone, middle tone, and shadow tone by using a color scanner for electronic color separation. For tones, set the cut point of original density to 0.6
The range of 1.2, the shadow point is set to the cut point of the original density of 1.2, and the special gradation is set in the color scanner to reproduce the gradation in the range of 1.2 or more. The continuous toning separation film thus prepared is applied to a plate material for lithographic printing by contact exposure, development to form a printing plate, which is used for highlight tones. The solid density is 0.3 to 0.
6. The full tone of the original is reproduced by overprinting with a printing ink with a solid density of 0.7 to 1.0 for middle tones and a solid density of 1.3 to 1.6 for shadow tones. Method for producing screenless printed matter, and
It is a screenless printed matter manufactured using the same.

A continuous disintegrated film is used as a plate material for lithographic printing.
The method of producing a printed matter without contact by closely adhering to it has been tried many times in the past, but since the purpose of the planographic printing plate itself is to reproduce halftone dots, a continuous tone decomposition film is printed. However, the gradation expression becomes very hard.

Therefore, even if the continuous tone decomposition film is contact-exposed and printed with a developed plate, the gradation reproduction density range is about 0.6 in the density range of the continuous tone decomposition film, and the total density range is about 1. It is 1/3 of 0.8. For this reason, in the method of the above-mentioned publication, one continuous-tone film is used, and the lithographic printing plate material is exposed three times by changing the exposure amount to produce each of the color separation plates for highlight, middle, and shadow. Was there. However, in this method, the amount of change in the amount of exposure is large and there is an unstable element. Therefore, the improved method is the method of the present invention.

That is, it is an electronic plate making machine having good disassembly accuracy at the stage of producing a continuous tone disintegrating film instead of producing a separation plate by changing the exposure amount and baking it on a plate material for lithographic printing. Using color scanner, prepare separation films for highlight, middle and shadow areas for separation, expose the decomposition films under exposure conditions suitable for ordinary planographic printing plates, develop and print To obtain a separate plate for.

[0011]

According to the present invention, a color scanner for electronic color separation is used to divide into highlight tone, middle tone and shadow tone, and for highlight tone, the range of document density is from 0 to 0.6. For the middle tone, set the original density cut point to 0.6 and the range is 0.6 to 1.2. For the shadow point, set the original density cut point to 1.2 and the gradation is 1.2 or more. Since a special gradation for reproduction is set in the color scanner and color separation is performed, it is possible to always obtain a stable and accurate printing plate separation.

[0012]

Embodiments will be described below according to embodiments. The normal continuous color separation film has a photographic density of about 0 to 1.8,
FIG. 3 shows the gradation reproduction at the time of printing with a printing ink having a solid density of 1.5 on a plate which was subjected to contact exposure and development on a planographic printing plate material. From this, the density of the continuous toning separation film that can be expressed by the planographic printing plate material is about 0.5 to 0.6. Therefore, when color separation of an original color film is performed by a color scanner, a curve that reproduces highlight tones, middle tones, and shadow tones is set in the color scanner, and color separation is performed using this gradation curve.

This gradation curve is shown in FIG.
Since the density range of the continuous film that can be reproduced with the planographic printing plate material is 0.5 to 0.6, the blackening density in the continuous tone film is set to about 0.8, and the gradation curve for the highlight tone is (a ), The gradation curve for middle tone has the density cut point set to 0.6 as the original density, and the gradation curve for shadow tone has the cut point set to 1.2 as shown in (b). The gradation curve set in this way was used for decomposition. A plate is made with a plate material for lithographic printing using a continuous tone film. The ink for highlight tone has a solid density of 0.3, the ink for middle tone has a solid density of 0.9, and the ink for shadow tone has a solid density of 0.9. The ink is an ink prepared so that the solid density becomes a reflection density of 1.5, and is printed with the registration.

FIG. 2 shows a print reproduction curve for the original at this time. A is a plate using a continuous tone film disassembled in (a) for highlight tones, and is printed with a solid density of 0.3. Similarly, B and C are printed using (b) and (c). Edition,
The gradation is reproduced when the solid density is printed at 0.9 and 1.5, and the gradation is reproduced when overprinted, and the full tone of the original can be reproduced.

In the above, one color of overprinting, for example, magenta color has been described, but the same applies to other yellow, cyan and black colors. Usually, by printing these four colors, the same color as normal printing is obtained. Reproduction and gradation reproduction can be measured.

The main equipment and materials used in the above examples are as follows. Color scanner: DC-300 (German Hell) Photosensitive material: SC-21 (Fuji Photo Film Co., Ltd.)
Plate material for lithographic printing: PS plate (manufactured by Photochemical Co., Ltd.) Printing machine: Flatbed proofing machine (manufactured by Dainippon Screen Mfg. Co., Ltd.) Ink: Light resistance mark V (manufactured by Toyo Ink Mfg. Co., Ltd.) Medium : TK School OP (Toyo Ink Manufacturing Co., Ltd.)
Manufacture) In addition, the materials and methods used in ordinary photolithography and lithographic printing were used.

[0017]

EFFECTS OF THE INVENTION It is possible to easily create a screenless printed matter without halftone dots, which is similar to a photograph, and since the photoengraving technique is applied, the working process can be standardized and the working time until the printing plate is made can be made. It is possible to greatly reduce the cost and cost.
Further, the number of printing plates to be created can be reduced as compared with the lithograph.

[0018]

[Brief description of drawings]

FIG. 1 is a graph of original density vs. color separation film density showing a special gradation curve set in a color scanner used in the present invention.

FIG. 2 is a graph of document density-print reflection density showing screenless print gradation reproduction of the present invention.

[Fig. 3] A continuous continuous color separation film is exposed to a plate material for lithographic printing by contact exposure, and the plate developed shows a gradation reproduction at the time of printing with a printing ink having a solid density of 1.5. It is a graph of concentration.

[Explanation of sign]

A ... A curve was produced using a continuous tone film disassembled using the curve (a), and a curve was printed at a solid density of 0.3. B ... A continuous tone film disassembled using the curve (b) was used. Curve D produced by making a lithographic printing plate and printing it with a solid density of 0.9. Curve D produced by using a continuous tone film decomposed using curve C (curve C) and printing with a solid density of 1.5. ... Gradation reproduction curve when curves A, B, and C are overlaid (a) ... Highlight tone gradation curve (b) ... Middle tone gradation curve
(C) ... Shadow tone gradation curve

Claims (2)

[Claims] 1. A method of producing a screenless printed matter by contact-exposure and developing a continuous toning separation film on a plate material for lithographic printing, wherein the continuous toning separation film is an electronic color. Using a color scanner for separation, it is divided into highlight tone, middle tone, and shadow tone. For highlight tone, the original density is 0 to 0.
6, the cut point of the original density is set to 0.6 for the middle tone, and the range of 0.6 to 1.2 is set for the shadow tone, and the cut point of the original density is set to 1.2 for the shadow points.
A special gradation which is designed to reproduce gradations in two or more ranges is set in the color scanner, color separation is performed, and the continuous toning separation film thus created is used for lithographic printing. The plate material is contact-exposed and developed to form a printing plate. The printing plate is used to obtain a solid density of 0.3 to 0.6 for highlight tones and a solid density of 0.7 to 1 for middle tones. 0.0, solid density 1.3 for shadow tones
A method for producing a screenless printed matter, which is characterized in that a full tone of an original is reproduced by performing overprinting with a printing ink toned to 1.6. 2. A screenless printed matter produced by the method according to claim 1.