CN112297667A

CN112297667A - Color gamut frequency modulation screen printing process based on XCMYK expansion

Info

Publication number: CN112297667A
Application number: CN202011045432.6A
Authority: CN
Inventors: 郑彩虹; 戴胜利; 王玉叶
Original assignee: STARLITE PRINTING (SUZHOU) CO LTD
Current assignee: STARLITE PRINTING (SUZHOU) CO LTD
Priority date: 2020-09-29
Filing date: 2020-09-29
Publication date: 2021-02-02

Abstract

The invention discloses a XCMYK (X-ray diffraction-based) extended color gamut frequency modulation screen printing process, which comprises the following steps of: according to ISO 12647: 2013, selecting 200g of coated paper for printing; and selection of four-color inks: cyan ink, Lab values L =54, a = -41, b = -45; magenta ink having a Lab value of L =52, a = -79, b = -9; yellow ink, Lab values L =90, a = 7, b = 102; black ink; then the printing work: inputting the TC1617 color table into a printer, and adopting a G7 method to make a prepress publishing compensation curve for color calibration; increasing the thickness of a blanket pad in a printing apparatus to increase the pressure between a blanket cylinder and an impression cylinder of a printing press; and (3) selecting 15-micron frequency modulation dot printing, controlling the printing solid density of each ink area to be uniform, wherein the dot expansion value of each ink area is the same, and the dot data requirements of the four-color plate are consistent. The printing process provided by the invention is simple to operate and low in cost, can enhance the visual effect and improve the packaging value, and has great significance and market value for the packaging industry.

Description

Color gamut frequency modulation screen printing process based on XCMYK expansion

Technical Field

The invention relates to a color gamut frequency modulation screen printing process based on XCMYK expansion, and belongs to the technical field of printing.

Background

In the current offset printing technology, four-color printing is a conventional printing technology, and is a four-color printing mode of CMYK (CMY is the first letter of the names of 3 printing inks, namely Cyan Cyan, Magenta and yellow, and K takes the last letter of Black Black). Due to the limited color gamut of the four-color ink, the original information which can be restored by the four-color printed matter is limited, and the aim of maximally reproducing the colors of the original cannot be achieved.

The screening methods commonly used in the printing industry for image reproduction are amplitude and frequency modulated screening. Amplitude modulation screening is to keep the quantity and arrangement of the screen dots unchanged, and the color and density are controlled by the size change of the screen dot diameter; to reduce the magnitude of a given color in a particular area, the number and arrangement of dots is maintained and the dot diameter is reduced. In this screening method, many regular rosette-type streaks and even moire patterns may occur due to the four-color overprinting. In addition, since the image has to be subjected to halftone decomposition during the screening process, the image sharpness is rapidly reduced with the decrease of the number of halftone lines, and the features of the original are lost. Meanwhile, the screening line number exceeds a certain limit, which not only brings more difficulty to printing, but also causes more serious loss of color gradation, especially highlight part, and is the biggest defect of the traditional amplitude modulation screening method.

Disclosure of Invention

The purpose is as follows: in order to overcome the defects in the prior art, the invention provides an XCMYK-based color gamut expanding frequency modulation screen printing process.

The technical scheme is as follows: in order to solve the technical problems, the technical scheme adopted by the invention is as follows:

a color gamut frequency modulation screen printing process based on XCMYK expansion,

preparation before printing, comprising: according to ISO 12647: 2013, selecting 200g of coated paper with high whiteness, high stiffness and good ink absorption for printing; and selection of four-color inks: cyan ink, Lab values L =54, a = -41, b = -45; magenta ink having a Lab value of L =52, a = -79, b = -9; yellow ink, Lab values L =90, a = 7, b = 102; black ink;

printing: inputting the TC1617 color table into a printer, and adopting a G7 method to make a prepress publishing compensation curve for color calibration; increasing the thickness of a blanket pad in a printing apparatus to increase the pressure between a blanket cylinder and an impression cylinder of a printing press; selecting 15-micron frequency modulation dot printing, controlling the printing solid density of each ink area to be uniform, controlling the dot expansion value of each ink area to be the same, and controlling the dot data of the four-color plate to be consistent, wherein the dot control standard of the four-color plate is as follows: the area rate of 20% of the dots on the printed matter is 26%, the area rate of 50% of the dots on the printed matter is 65%, and the area rate of 70% of the dots on the printed matter is 90%.

Further, the printing solid density of the ink area of each color was: the cyan ink area was 1.6, the magenta ink area was 1.4, the yellow ink area was 1.25, and the black ink area was 1.9.

Further, the blanket pad has a thickness of 0.5-2.1 mm.

Further, the error of dot gain value on the four-color plate is

1%。

Further, the dot gain error of the printed matter is

1%。

Further, the ink used has no more than 5% of viscosity-removing agent added therein.

Has the advantages that: the XCMYK-based color gamut expanding frequency modulation and screen printing process has the advantages of higher color saturation after color gamut expansion, visual effect enhancement, packaging value improvement, simple operation, low cost, stable quality, capability of meeting the existing market demand, cost reduction, resource saving and great significance and market value for the packaging industry.

Detailed Description

The present invention will be further described with reference to the following examples.

A color gamut frequency modulation screen printing process based on XCMYK extension is firstly prepared before printing and comprises the following steps: according to ISO 12647: 2013, selecting 200g of coated paper with high whiteness, high stiffness and good ink absorption for printing; and selection of four-color inks: cyan ink, Lab values L =54, a = -41, b = -45; magenta ink having a Lab value of L =52, a = -79, b = -9; yellow ink, Lab values L =90, a = 7, b = 102; black ink.

The ink is added with no more than 5 percent of viscosity removing agent, so that the smoothness of the surface of the ink is improved, and the light reflection area is expanded.

Printing: inputting the TC1617 color table into a printer, and adopting a G7 method to make a prepress publishing compensation curve for color calibration; the thickness of the blanket pad in the printing equipment is increased to be 0.5-2.1mm, so that the pressure between the blanket cylinder and the impression cylinder of the printing machine is increased, the smoothness is improved, the better reflection of the color of the ink is facilitated, meanwhile, the limiting, permeating and absorbing of the ink on paper is promoted, and the coverage of the ink on the paper is increased.

Selecting 15-micron frequency modulation screen dot printing, and controlling the printing solid density of each ink area to be uniform, wherein the printing solid density of each ink area is as follows: the cyan ink area was 1.6, the magenta ink area was 1.4, the yellow ink area was 1.25, and the black ink area was 1.9. The dot expansion values of all the ink areas are the same, the dot data of the four-color plate are required to be consistent, and the dot control standard of the four-color plate is as follows: the area rate of 20% of the dots on the printed matter is 26%, the area rate of 50% of the dots on the printed matter is 65%, and the area rate of 70% of the dots on the printed matter is 90%.

Dot gain error of four-color plate

1%, the error of dot gain value of the printed matter is

1%。

The above description is only of the preferred embodiments of the present invention, and it should be noted that: it will be apparent to those skilled in the art that various modifications and adaptations can be made without departing from the principles of the invention and these are intended to be within the scope of the invention.

Claims

1. An XCMYK-based color gamut expanding frequency modulation screen printing process is characterized in that,

2. The XCMYK-based extended color gamut frequency-modulated screen printing process as defined in claim 1, wherein the printing solid density of the ink area of each color is as follows: the cyan ink area was 1.6, the magenta ink area was 1.4, the yellow ink area was 1.25, and the black ink area was 1.9.

3. The XCMYK extended color gamut fm screen printing based process according to claim 1, wherein the blanket liner thickness is 0.5-2.1 mm.

4. The XCMYK-based extended color gamut FM screen printing process as recited in claim 1, wherein the dot gain value error on the four-color plate printing plate is

1%。

5. The XCMYK-based extended color gamut frequency-modulated screen printing process as defined in claim 1, wherein the dot gain error of the printed matter is

1%。

6. A XCMYK-based extended color gamut fm screen printing process as claimed in claim 1 wherein no more than 5% of viscosity-reducing agent is added to the ink used.