CN111363402A - Red special color ink for conch bead offset printing - Google Patents

Abstract

The invention discloses a conch bead red spot color ink for offset printing, which is composed of the following raw materials by mass percentage: 8.0-9.0% of red ink; 80.0-81.0% of pink ink; and 11.0-12.0% of transparent ink. By adopting the formula of the invention to prepare the Conch Pearl red spot color ink for offset printing, the Conch Pearl red spot color ink (Conch Pink) can be used to replace the Magenta primary color ink in the four primary colors Cyan/Magenta/Yellow/Black of offset lithographic printing, and the Conch Bead The red spot color ink (Conch Pink) uses the bright and saturated pink (Rhodamine) and red (Rubine Red) pigments. Compared with the magenta ink, the color of the conch pearl red spot color ink is brighter, the saturation is higher, and the hue is partial. Blue, to meet the needs of lithographic offset primary color use.

Description

A kind of conch pearl red spot color ink for offset printing

technical field

The invention relates to the technology in the field of ink, in particular to a conch pearl red spot color ink for offset printing.

Background technique

There is no doubt that ISO 12647-2 "Printing Technology - Process Control of Halftone Separations, Proofs and Finished Printed Products - Part 2: Offset Printing" is the most widely used offset printing process standard for printing companies. This standard is a strong basis for the evaluation and correction of printing standardization. With it, printing standardization and process control can be carried out effectively. The standard was promulgated in 1996 and revised in 2004 and 2013 respectively. At present, the ISO12647-2 standard implemented by printing companies in offset printing production is mostly the 2004 version, and there is some gap between this standard and the current actual printing conditions. Therefore, it is necessary for printing companies to follow the 2013 version of ISO 12647-2 standard. The printing process is re-controlled.

The main differences between the 2004 version and the 2013 version of the ISO 12647-2 standard:

The main differences between the 2004 version and the 2013 version of the ISO 12647-2 standard are reflected in the defined paper type, ink color, and dot gain rate.

1. Paper type: The 2013 version of the standard defines a new 8 types of paper, changing the paper type from 5 to 8, and the CIE Lab chromaticity value of the paper also changes accordingly. The paper types defined by the 2013 version of the standard are closer to the paper types used by most domestic printing companies and are more in line with actual production.

2. Ink color: The 2013 version of the standard changes the ink color from 5 to 8 according to the paper type it defines, and the CIE Lab chromaticity value of the ink color also changes accordingly. Depending on the paper type, it is reasonable to update the ink color accordingly.

3. Dot increase rate: Under the current mainstream CTP platemaking process, a larger increase in tone value occurs in the bright tone part, which is contrary to the situation in the 2004 version of the standard, where a larger increase in tone value occurs in the 2004 version of the standard. In the midtones and shadows.

The control process of realizing ISO 12647-2:2013 standard in the digital proofing link:

Taking GMG digital proofing software as an example, this paper introduces the control process of realizing ISO 12647-2:2013 in the digital proofing process.

1. Input the ICC file: In the GMG digital proofing software, input the ICC file (PSO Coated V3.icc, that is, Fogra51.icc) that conforms to the ISO 12647-2:2013 standard, as the target value of the digital proofing.

2. Cyclic correction of digital proofing: use the digital proofing machine to output the ECI2002_CMYK_iO.tif test sample, and measure it with a spectrophotometer, take the measured data as the current value of the digital proofing, and compare it with the target value to obtain the maximum ΔE and average ΔE And the number of color blocks with ΔE>3, if the proofing result does not meet the standard requirements, calculate the target value and the current value, and reprint; if it meets the requirements, end the process control.

Offset printing involves CIE Lab and CIE Lch color space, color gamut, hue and saturation: Among them, CIE Lab is a color system of CIE, the color system, based on CIE Lab means based on this color system, basically using It is used to determine the numerical information of a certain color; the CIE Lch color space adopts the same color space as L*a*b*, but it uses L to represent the lightness value; C to represent the saturation value and H to represent the cylindrical coordinate of the hue angle value; Color gamut is a method of encoding a color. It also refers to the sum of the colors that a technical system can produce. In computer graphics processing, a color gamut is a complete subset of colors. The most common application of color subsets is Used to accurately represent a given situation, such as a given color space or the color rendering range of a certain output device; hue is the primary characteristic of color, the most accurate standard for distinguishing various colors, the fact Any color other than black, white and gray on the above has the attribute of hue, and hue is composed of primary colors, secondary colors and complex colors. Hue, the texture and appearance of colors, and different hues in nature are infinitely rich. Such as purple red, silver gray, orange yellow, etc., hue is the appearance of various colors; saturation can be defined as chroma divided by lightness, and chroma is the same as the degree to which a color deviates from gray with the same brightness. Note that it is not the same as chroma. The concept, but because it and chroma determine the same effect that appears in the human eye, it will appear that chroma and saturation are the same concept.

The current lithographic offset printing is based on the ISO 12647-2:2013 standard offset printing, lithography, as the name implies, refers to the printing plate with the graphic and blank on the printing surface on a flat surface. The ink of the graphic part is transferred to the substrate by an indirect method through the blanket, which is referred to as lithographic offset printing. In the prior art, lithographic offset printing usually uses 4 primary colors to reproduce product colors, namely Cyan (cyan)/Magenta (magenta)/Yellow (yellow)/Black (black); the primary color ink is affected by the color of the pigment itself, resulting in The actual color differs from the theoretical target, especially with Magenta (magenta); the flaws are as follows:

1. The color of Magenta ink is yellowish; it causes the color of Cyan + Magenta + Yellow + Black four-color prints to be yellowish.

2. The saturation of Magenta ink is low; the color of Cyan + Magenta + Yellow + Black four-color prints is darker, not bright enough, and cannot meet the needs of use.

Therefore, it is necessary to study a scheme to solve the above problems.

SUMMARY OF THE INVENTION

In view of this, the present invention aims at the deficiencies existing in the prior art, and its main purpose is to provide a conch bead red spot color ink for offset printing, which can effectively improve Cyan + Magenta + Yellow + Black conventional four-color prints with darker, more Yellow shortcomings.

To achieve the above object, the present invention adopts the following technical scheme:

A conch bead red spot color ink for offset printing is composed of the following raw materials by mass percentage: 8.0-9.0% of large red ink; 80.0-81.0% of pink ink; 11.0-12.0% of transparent ink.

As a preferred version, the color value of the Conch Pearl red spot color ink for the offset printing is: L 48.0 a 83.5 b-18.0, and the measuring instrument adopted is X-rite Exact, and the color is set; Measuring condition: M1; Light source and viewing angle : D50/2°; Color difference formula: CIE △E (2000); Color difference requirement: △E<1.5.

Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be known from the above technical solutions:

By adopting the formula of the invention to prepare the Conch Pearl red spot color ink for offset printing, the Conch Pearl red spot color ink (ConchPink) can be used to replace the Magenta primary color ink in the four primary colors Cyan/Magenta/Yellow/Black of offset lithographic printing, and the Conch Pearl red spot color ink Spot color ink (Conch Pink) uses bright and saturated peach red (Rhodamine) and red (RubineRed) pigments. Compared with magenta ink, Conch Pearl red spot color ink is brighter, more saturated, and has a bluish hue. Meet the needs of lithographic offset printing primary colors.

Description of drawings

Fig. 1 is the color contrast schematic diagram of the preferred embodiment of the present invention and magenta ink;

Fig. 2 is the preferred embodiment of the present invention and the color gamut comparison schematic diagram of magenta ink;

FIG. 3 is a schematic diagram showing the comparison between a preferred embodiment of the present invention and a sample of magenta ink.

Detailed ways

The invention discloses a conch bead red spot color ink for offset printing, which is composed of the following raw materials by mass percentage: Rubine Red 8.0-9.0%; Rhodamine 80.0-81.0%; Trans White 11.0% -12.0%, the formula of Conch Pearl Red spot color ink for offset printing is preferably: big red ink 8.5%; pink ink 80.5%; transparent ink 11.0%. The color value of the conch pearl red spot color ink for the offset printing is: L 48.0 a 83.5 b -18.0, and the measuring instrument adopted is X-rite Exact, and the color is set; Measuring condition: M1; Light source and viewing angle: D50/2°; Color difference formula: CIE △E (2000); Color difference requirement: △E<1.5.

During production, the red ink, pink ink and transparent ink are mixed evenly in proportion to obtain Conch Pink spot color ink for offset printing.

Contrast the conch pearl red spot color ink and magenta ink for offset printing of the present invention:

First, the color value of the magenta ink (Magenta) is: L 48.0 a 73.5 b -5.2. From the color data of the two inks, it is found that the Conch Pink spot color ink (Conch Pink) for offset printing of the present invention is better than the magenta ink ( Mageneta) a value is darker, b value is relatively small, as shown in Figure 1, Conch Pink for offset printing is brighter in color and higher in saturation than magenta ink (Mageeta), and the overall visual effect has a partial hue. blue.

Secondly, as shown in Figure 2, the color gamut comparison diagram of Cyan + Conch Pink + Yellow + Black four-color printing and Cyan + Magenta + Yellow + Black four-color printing, the blue line area is the CMYK color gamut, and the gray line area is the CCYK color The color gamut of the Conch Pink spot color ink (Conch Pink) for offset printing of the present invention is much larger than that of the magenta ink (Magenta) in the red, purple and orange interval, and can better restore the color of the printed product.

ISO12647-2 (2013) primary color target value (CIE Lab color space):

Subtrate: L 95.0 a 1.5 b -6.0;

Cyan: L 56.1 a -34.9 b 52.5;

Magenta: L 48.0 a 75.3 b -5.2;

Yellow: L 88.9 a -4.0 b 92.4;

Black: L 16.0 a 0.1 b -0.3;

CCYK primary color target value (CIE Lab color space;

Subtrate: L 95.0 a 1.5 b -6.0;

Cyan: L 56.1 a -34.9 b 52.5;

Conch Pink: L 48.0 a 83.5 b -18.0;

Yellow: L 88.9 a -4.0 b 92.4;

Black: L 16.0 a 0.1 b -0.3.

Furthermore, as shown in Figure 3, Cyan + Conch Pink + Yellow + Black four-color printing and Cyan + Magenta + Yellow + Black four-color printing proof color comparison chart, the present invention uses Conch Pearl red spot color ink (Conch Pink) for offset printing The printed sheet is obviously brighter than the magenta ink (Magenta), with a purplish red color, and the whole is bright, and the yellowish and insufficient saturation of the magenta ink (Magenta) has been significantly improved.

The key point of the design of the present invention is: by adopting the formula of the present invention, the Conch Pearl red spot color ink for offset printing is prepared, and the Conch Pearl red spot color ink (Conch Pink) can be used to replace the Magenta in the four primary colors Cyan/Magenta/Yellow/Black of lithographic offset printing. Primary color ink, and Conch Pink uses bright and saturated peach (Rhodamine) and red (Rubine Red) pigments. Compared with magenta ink, Conch Red spot color ink is more bright and saturated. The degree of intensity is higher, and the hue is bluish, which meets the needs of the primary color of lithographic offset printing.

The above are only preferred embodiments of the present invention, and do not limit the technical scope of the present invention. Therefore, any minor modifications, equivalent changes and modifications made to the above embodiments according to the technical essence of the present invention are still It belongs to the scope of the technical solution of the present invention.

Claims (2)

1. A conch bead red spot color ink for offset printing, characterized in that: it is made up of the following mass percentage raw materials: 8.0-9.0% of big red ink; 80.0-81.0% of pink ink; 11.0-12.0% of transparent ink. 2. a kind of conch bead red spot color ink for offset printing according to claim 1, is characterized in that: the color value of the conch bead red spot color ink for described offset printing is: L 48.0a83.5b-18.0, the measurement that adopts The instrument is X-riteExact, color setting; measurement condition: M1; light source and viewing angle: D50/2°; color difference formula: CIE △E (2000); color difference requirement: △E<1.5.

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