Spot color plate making method

Abstract

The present disclosure provides a method for making spot color plates, comprising the following steps. A concentration step test is performed on a target fabric to generate a concentration characteristic curve of the target fabric. A computer software is used to separate a target pattern into a first group of spot color patterns. A first spot color concentration curve is generated based on the concentration characteristic curve and the first group of spot color patterns. The first spot color concentration curve is compressed to form a second group of spot color concentration curves. A straight line connecting the highest value and the lowest value of the second group of spot color concentration curves is set as a standard line. A reverse compensation curve is generated by subtracting the difference between the second group of spot color concentration curves and the standard line from the standard line. A second group of spot color patterns is generated based on the reverse compensation curve and the first group of spot color patterns. A plurality of spot color plates of the target pattern are made based on the second group of spot color patterns.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a method for making a special color plate, in particular to a method for making a special color plate for printing a high color rendering color pattern on a dark fabric. BACKGROUND

[0002] Traditional screen printing technology is very mature and has been widely used in various fabrics with different properties. Since screen printing requires the preparation of a special color plate in advance, the patterns that can be printed by screen printing are mainly simple color blocks or simple gradations, and complex patterns cannot be printed.

[0003] In recent years, digital printing technology has been developed, which can print color-rich patterns and does not require the preparation of a special color plate. Digital printing technology mainly uses the principle of superposition and halftone color mixing to simulate continuous color changes by changing the size and / or frequency of ink dots of each color. However, digital printing technology requires a large upfront investment. Moreover, the fabric materials and fabric base colors suitable for digital printing technology are still limited. Digital printing technology is particularly difficult to apply to dark fabrics and denim fabrics. Dark fabrics or denim fabrics often have too dark base colors, which makes it difficult for color patterns to develop successfully.

[0004] Currently, the color fading (color pulling) technology is often used to fade dark fabrics, and then color patterns are printed on the faded areas. However, the color fading technology uses chemical agents to produce reduction or oxidation reactions on dark fabrics. Subsequently, in order to remove the chemical agents, repeated washing or drying is required. In addition to the chemical agents causing environmental pollution, subsequent processing also consumes a lot of water resources and energy. SUMMARY

[0005] The present disclosure combines the traditional printing technology plate making method and the superposition and halftone color mixing principle of digital printing to provide a special color plate making method that can be used to print high color rendering color patterns on dark fabrics.

[0006] The present disclosure provides a special color plate making method comprising the following steps. Perform a concentration level test on a target fabric to generate a concentration characteristic curve of the target fabric. Perform color separation processing on a target pattern using computer software to separate the target pattern into a first group of special color patterns. Generate a first special color concentration curve based on the concentration characteristic curve and the first group of special color patterns. Compress the first group of special color concentration curves to form a second group of special color concentration curves. Connect the highest value and the lowest value of the second group of special color concentration curves to form a standard line. Subtract the difference between the second group of special color concentration curves and the standard line from the standard line to form a reverse compensation curve. Generate a second group of special color patterns based on the reverse compensation curve, the first group of special color concentration curves, and the first group of special color patterns. Make a plurality of special color plates for the target pattern based on the second group of special color patterns.

[0007] In some embodiments, the concentration step test comprises the following steps. Printing a concentration step of the test color with a concentration of 1% to 100% on the target fabric along a first direction, a second direction, a third direction, and a fourth direction. Detecting the color developing concentration of the test color on the target fabric. Averaging the color developing concentration along the first direction, the second direction, the third direction, and the fourth direction to generate a concentration profile of the target fabric.

[0008] In some embodiments, the first direction and the second direction are perpendicular to each other, the first direction and the third direction are parallel to each other and opposite, and the fourth direction and the second direction are parallel to each other and opposite.

[0009] In some embodiments, the color separation process comprises separating the target pattern into four to ten colors, such that the first set of spot color patterns comprises four to ten first spot color patterns.

[0010] In some embodiments, the color separation process comprises separating the target pattern into four colors, such that the first set of spot color patterns comprises a first cyan color pattern, a first magenta color pattern, a first yellow color pattern, and a first black color pattern.

[0011] In some embodiments, the color separation process comprises separating the target pattern into six colors, such that the first set of spot color patterns comprises a first cyan color pattern, a first magenta color pattern, a first yellow color pattern, a first black color pattern, a first orange color pattern, and a first green color pattern.

[0012] In some embodiments, the compressing the first set of spot color concentration curves comprises multiplying the values of the first set of spot color concentration curves by 0.6 to 0.8.

[0013] In some embodiments, the material of the target fabric comprises cotton, rayon, polyester fiber, nylon fiber, spandex, silk, or a combination thereof.

[0014] In some embodiments, the color range of the target fabric is between dark gray (RGB(110, 110, 110)) and black (RGB(0, 0, 0)).

[0015] In some embodiments, the making the plurality of spot color plates of the target pattern according to the second set of spot color patterns comprises the following steps. Coating a photosensitive agent on a screen. Allowing the photosensitive agent on the screen to dry. Engraving the screen to form a spot color plate according to the second set of spot color patterns. BRIEF DESCRIPTION OF DRAWINGS

[0016] Various aspects of the disclosure can be more fully understood from the following detailed description, taken in connection with the accompanying drawings, in which like reference numerals represent like elements or features, and in which:

[0017] Figure 1A flowchart of a manufacturing method of a spot color plate according to some embodiments of the present disclosure is shown;

[0018] Figure 2 A schematic diagram of a concentration step test sample according to some embodiments of the present disclosure is shown;

[0019] Figure 3 A schematic diagram of a target artwork according to some embodiments of the present disclosure is shown;

[0020] Figures 4 to 7 A schematic diagram of a first spot color generated after color separation of a target artwork according to some embodiments of the present disclosure is shown;

[0021] Figures 8 to 11 A schematic diagram of a first spot color concentration curve according to some embodiments of the present disclosure is shown;

[0022] Figures 12 to 15 A schematic diagram of a relationship between a second spot color concentration curve, a standard line and a reverse compensation curve according to some embodiments of the present disclosure is shown.

[0023]

Symbol Description

[0024] 100: method

[0025] 200: target artwork

[0026] 200C: first cyan color pattern

[0027] 200M: first magenta color pattern

[0028] 200Y: first yellow color pattern

[0029] 200K: first black color pattern

[0030] C1: first cyan color concentration curve

[0031] C2: second cyan color concentration curve

[0032] C3: cyan color standard line

[0033] C4: cyan color reverse compensation curve

[0034] M1: first magenta color concentration curve

[0035] M2: second magenta color concentration curve

[0036] M3: magenta color standard line

[0037] M4: magenta color reverse compensation curve

[0038] Y1: first yellow color concentration curve

[0039] Y2: second yellow color concentration curve

[0040] Y3: yellow standard line

[0041] Y4: yellow inverse compensation curve

[0042] K1: first black density curve

[0043] K2: second black density curve

[0044] K3: black standard line

[0045] K4: black inverse compensation curve

[0046] D1: first direction

[0047] D2: second direction

[0048] D3: third direction

[0049] D4: fourth direction

[0050] S102, S104, S106, S108, S110, S112, S114, S116: steps DETAILED DESCRIPTION

[0051] To make the description of the disclosure more detailed and complete, the aspects and embodiments of the disclosure are described below in an exemplary manner. Although the method of the disclosure is illustrated below by a series of operations or steps, the order shown by these operations or steps should not be interpreted as a limitation of the disclosure. For example, certain operations or steps can be performed in a different order and / or simultaneously with other steps. In addition, not all of the illustrated operations, steps and / or features must be performed to implement embodiments of the disclosure, each operation or step described herein can include several sub-steps or actions.

[0052] Generally, "about" as used herein with respect to a numerical value or range means an error or range of approximately twenty percent, preferably approximately ten percent, and more preferably approximately five percent. Unless otherwise specified, all numerical values mentioned herein are considered to be approximate, i.e., within the error or range indicated by "about".

[0053] The disclosure provides a method 100 for manufacturing a spot color plate. Figure 1 A flowchart of the method 100 for manufacturing a spot color plate is shown according to some embodiments of the disclosure. In step S102, a concentration level test is performed on a target fabric, and a concentration characteristic curve of the target fabric is generated.

[0054] In some embodiments, the target fabric is a dark fabric. The color of the target fabric can be black, dark gray, dark blue, dark green, dark purple, etc. For example, the color of the target fabric ranges between dark gray (RGB(110, 110, 110)) and black (RGB(0, 0, 0)). In some embodiments, the material of the target fabric can include cotton, rayon, polyester, nylon, spandex, silk, or a combination thereof. In some embodiments, the target fabric can be denim.

[0055] Reference is made to Figure 2 . Figure 2 A schematic diagram of a concentration step test pattern is shown according to some embodiments of the present disclosure. Specifically, the concentration step test is to print out concentration steps of 1% to 100% of a test color on a target fabric along a first direction D1, a second direction D2, a third direction D3, and a fourth direction D4, respectively, with 1% as a unit. In some embodiments, concentration refers to the amount of pigment in each cell or the area of the cell that is colored by the pigment. As shown in Figure 2 , the first direction D1 and the second direction D2 are perpendicular to each other. The first direction D1 and the fourth direction D4 are perpendicular to each other, and the fourth direction D4 and the second direction D2 are opposite to each other. The first direction D1 and the third direction D3 are parallel to each other and opposite to each other.

[0056] In some embodiments, one concentration step test is performed using one test color. In some embodiments, the test color is black (Black, K). In some embodiments, four concentration step tests are performed using four colors, respectively, wherein the four colors include cyan (Cyan, C), magenta (Magenta, M), yellow (Yellow, Y), and black (Black, K).

[0057] Next, the color development concentration of the test color in each cell in the concentration step is detected on the target fabric. Then, the color development concentration of each concentration along the four directions is averaged, respectively, to generate a concentration characteristic curve of the target fabric.

[0058] Since the texture of different fabrics can also affect the color development of a printed color pattern, concentration step tests of 1% to 100% are performed along four different printing directions. In addition to being able to know the concentration development characteristics of the dye on this fabric, it can also be known whether there are color development differences in different printing directions of this fabric.

[0059] Reference is made to Figure 1 and Figure 3 . Figure 3According to some embodiments of the present disclosure, a schematic diagram of the target artwork 200 is shown. In step S104, the target artwork is separated into a first set of spot artwork by computer software color separation. In some embodiments, the target artwork can be pre-processed before color separation by computer software, for example, adjusting the color format of the target artwork to CMYK format.

[0060] Next, referring to Figure 1 and Figures 4 to 7 . Figures 4 to 7 According to some embodiments of the present disclosure, a schematic diagram of the first set of spot artwork generated after color separation of the target artwork 200 is shown. In some embodiments, the color separation includes separating the color artwork of the target artwork 200 into four color spot artwork of CMYK respectively. Specifically, the first set of spot artwork can include a first cyan spot artwork 200C( Figure 4 ), a first magenta spot artwork 200M( Figure 5 ), a first yellow spot artwork 200Y( Figure 6 ), and a first black spot artwork 200K( Figure 7 ).

[0061] In some embodiments, the color separation includes separating the target artwork 200 into six colors of CMYK, Orange (O), and Green (G) respectively, and generating a first cyan spot artwork 200C( Figure 4 ), a first magenta spot artwork 200M( Figure 5 ), a first yellow spot artwork 200Y( Figure 6 ), a first black spot artwork 200K( Figure 7 ), a first orange spot artwork (not shown), and a first green spot artwork (not shown).

[0062] In some embodiments, the color separation includes separating the target artwork into four to ten colors. In addition to the six commonly used colors mentioned above, users can pre-set special colors in the computer software according to their needs, such as fluorescent colors, metallic colors, and pearl colors. In some embodiments, the color separation includes determining the number of colors needed by the target artwork 200 by computer software, and then separating the target artwork 200 into four to ten first spot artwork. The plurality of first spot artwork is collectively referred to as the first set of spot artwork. In some embodiments, the target artwork 200 can be separated into more than ten colors. However, more than ten colors can cause difficulties in setting up the screen printing machine equipment in the subsequent process.

[0063] Next, referring to Figure 1 and Figures 8 to 11 . In step S106, according to the concentration characteristic curve and the first set of spot artwork, a first set of spot concentration curves corresponding to each color is generated. InFigures 8 to 11 In the figure, the horizontal axis is the input concentration (%), and the vertical axis is the output concentration (%). Figure 8 A first cyan concentration curve C1 is shown. Figure 9 A first magenta concentration curve M1 is shown. Figure 10 A first yellow concentration curve Y1 is shown. Figure 11 A first black concentration curve K1 is shown. The first special color concentration curves are collectively referred to as a first set of special color concentration curves. In some embodiments, when there are four first special color patterns, four corresponding first special color concentration curves are generated. In some embodiments, when there are N first special color patterns, N corresponding first special color concentration curves are generated.

[0064] Next, reference is made to Figure 1 and Figures 12 to 15 In step S108, the first set of special color concentration curves is compressed to form a second set of special color concentration curves. Compressing the first set of special color concentration curves means multiplying the values of the first set of special color concentration curves by 0.6 to 0.8 as a whole. The purpose of compressing the first set of special color concentration curves is to lighten the overall color of the target pattern, so that the target pattern is more clearly colored on dark fabric.

[0065] Figures 12 to 15 According to some embodiments of the present disclosure, a relationship diagram of the second special color concentration curve, the standard line, and the reverse compensation curve is shown. In Figures 12 to 15 In the figure, an embodiment in which the values of the first set of special color concentration curves are compressed to 70% of the original is shown. Figure 12 A second cyan concentration curve C2 is shown. Figure 13 A second magenta concentration curve M2 is shown. Figure 14 A second yellow concentration curve Y2 is shown. Figure 15 A second black concentration curve K2 is shown.

[0066] In step S110, a standard line is set. Specifically, a straight line connecting the highest value and the lowest value of the second set of special color concentration curves is set as the standard line. Figure 12 A cyan standard line C3 is shown. Figure 13 A magenta standard line M3 is shown. Figure 14 A yellow standard line Y3 is shown. Figure 15 A black standard line K3 is shown.

[0067] In step S112, a reverse compensation curve is set. Specifically, the difference between the second set of special color concentration curves and the standard line is subtracted from the value of the standard line. That is, the second set of special color concentration curves and the reverse compensation curve are symmetric with respect to the standard line. Figure 12 A cyan reverse compensation curve C4 is shown. Figure 13 A magenta reverse compensation curve M4 is shown. Figure 14 A yellow reverse compensation curve Y4 is shown.Figure 15 The black inverse compensation curve K4 is shown. Setting the inverse compensation curve further lightens the color of the colored pattern, allowing the colored pattern to appear better on dark fabrics.

[0068] In step S114, a second set of spot color patterns is generated. Based on the inverse compensation curve, the first set of spot color patterns, and the first set of spot color density curves, the second set of spot color patterns is generated. Specifically, the input density of the original first set of spot color patterns is multiplied by a compression value to obtain the adjusted output density on the inverse density compensation curve. The adjusted output density of the inverse density compensation curve is then mapped back to the predicted output density of the first spot color density curve to obtain the adjusted input density. The second set of spot color patterns is then generated using the adjusted input density.

[0069] In step S116, a spot color plate for the target pattern is created. Specifically, a spot color plate is created based on the second set of spot color patterns. Creating the spot color plate includes the following steps: First, a screen is provided, and a photosensitive agent or other suitable material is applied to the screen to fill each small square on the screen. The photosensitive agent on the screen is allowed to dry completely. Next, the second spot color pattern is input into a laser engraving machine. Based on the second spot color pattern, each small square on the screen is laser engraved to create openings in the screen. In some embodiments, when there are four second spot color patterns in total, four spot color plates are created corresponding to each pattern. From the viewpoint of conforming to common screen printing equipment settings, it is preferable to create four to ten spot color plates for one target pattern.

[0070] The spot color plates made using the method disclosed herein can print highly pigmented color patterns on dark fabrics. This method combines traditional printing plate-making techniques with the overlay and halftone mixing principles of digital printing. Unlike digital printing, it eliminates the need for substantial upfront investment in equipment construction, enabling the printing of rich and detailed colors. The method can be integrated into traditional printing plate-making processes. Printing on dark fabrics using spot color plates made using this method eliminates the need for pre-bleaching of the dark fabric, reducing environmental pollution and energy consumption.

[0071] Although this disclosure has been described in considerable detail with reference to some embodiments, other embodiments may also be possible. Therefore, the spirit and scope of the appended claims should not be limited to the description of the embodiments contained herein.

[0072] It will be apparent to those skilled in the art that various modifications and variations can be made to the structure of this disclosure without departing from its scope or spirit. In view of the foregoing, this disclosure is intended to cover any modifications and variations falling within the scope of the appended claims.

Claims

1. A method of making a spot color proof, characterized by, The method comprises: performing a concentration step test on a target fabric to generate a concentration characteristic curve of the target fabric; performing a color separation process on a target pattern by a computer software to separate the target pattern into a first set of spot color patterns; generating a first set of spot color concentration curves according to the concentration characteristic curve and the first set of spot color patterns; compressing the first set of spot color concentration curves to form a second set of spot color concentration curves; connecting a straight line between the highest value and the lowest value of the second set of spot color concentration curves as a standard line; subtracting the difference between the second set of spot color concentration curves and the standard line from the standard line as a reverse compensation curve; generating a second set of spot color patterns according to the reverse compensation curve, the first set of spot color concentration curves and the first set of spot color patterns; and manufacturing a plurality of spot color plates of the target pattern according to the second set of spot color patterns.

2. The method of claim 1, wherein, The concentration step test comprises: printing concentration steps of 1% to 100% of a test color on the target fabric along a first direction, a second direction, a third direction and a fourth direction; detecting a visible concentration of the test color on the target fabric; and averaging the visible concentrations along the first direction, the second direction, the third direction and the fourth direction to generate the concentration characteristic curve of the target fabric.

3. The method of claim 2, wherein, The first direction and the second direction are perpendicular to each other, the first direction and the third direction are parallel to each other and opposite, and the fourth direction and the second direction are parallel to each other and opposite.

4. The method of claim 1, wherein, The color separation process comprises: separating the target pattern into four to ten colors, so that the first set of spot color patterns comprises four to ten first spot color patterns.

5. The method of claim 1, wherein, The color separation process comprises: separating the target pattern into four colors, so that the first set of spot color patterns comprises a first cyan color pattern, a first magenta color pattern, a first yellow color pattern and a first black color pattern.

6. The method of claim 1, wherein, The color separation process comprises: separating the target pattern into six colors, so that the first set of spot color patterns comprises a first cyan color pattern, a first magenta color pattern, a first yellow color pattern, a first black color pattern, a first orange color pattern and a first green color pattern.

7. The method of claim 1, wherein, The compression of the first set of spot color concentration curves is multiplying the values of the first set of spot color concentration curves by 0.6 to 0.

8.

8. The method of claim 1, wherein, The material of the target fabric comprises cotton, lyocell, polyester fiber, nylon fiber, spandex, silk, or a combination thereof.

9. The method of claim 1, wherein, The color range of the target fabric is between dark gray (RGB(110, 110, 110)) and black (RGB(0, 0, 0)).

10. The method of claim 1, wherein, The manufacturing of the plurality of spot color plates of the target pattern according to the second set of spot color patterns comprises: coating a photosensitive agent on a screen; drying the photosensitive agent on the screen; and punching the screen to form the plurality of spot color plates by laser engraving according to the second set of spot color patterns.

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