TWI818843B - Method for producing spot color plates with high color rendering for dark fabrics - Google Patents

Abstract

The invention is a method for making a spot color plate with high color rendering that is applied to dark cloth. It uses the color separation plate making of traditional screen printing technology and combines it with the overlapping and half-tone color mixing principles of digital printing to dye and print high colors. To restore high-density color patterns, first, print the target fabric with at least four directions of 1% to 100% density levels according to the color of each color version, and obtain the highest and lowest concentration curve ranges of each color version; then, select a color finished artwork and separate it into Four or six first group of grayscale files; the first group of grayscale files are divided into the second group of grayscale files according to the maximum density value of 70% of the density curve range of each color version; according to the density curve range of each color version The straight line connecting 1% to 70% is the standard line, and the difference between the density curve and the standard line is used as the reverse density compensation value of the second grayscale file of each color version.

Description

Method for producing spot color plates with high color rendering for dark fabrics

The present invention relates to a method for making a spot color plate with high color rendering that can be used on dark cloth, and particularly refers to a method for making a spot color plate that can dye and print a color pattern with high color rendering on dark cloth.

The traditional screen printing technology is very mature and has been widely used on various fabrics with different characteristics. However, the patterns it can print are mostly simple color blocks or simple gradients. The reason is: screen printing It is limited by color separation plate making, and each color needs to be made in advance with a dedicated spot color plate, which is very time-consuming and labor-intensive. It also needs to be equipped with machine equipment that can support the number of printing plates. That is, if a certain printing design The picture has 15 colors. It is necessary to make 15 printing plates in advance to print the printing design, and then use the screen printing to print 15 spot color plates. For printing factories, most screen printing machines have the most equipment. It can only support 10~12 color block spot color versions, so the printing colors that can be printed are very limited.

In recent years, digital printing technology has been developed that has rich and detailed colors and does not require the production of spot color plates. It mainly uses the principles of overlapping colors and half-tone color mixing commonly used in the printing industry. The so-called half-tone color mixing technology is used to process tones in the traditional printing industry. And the method of simulating continuous tone, which mainly uses the changes in the size and frequency of ink dots sprayed by inkjet heads of various colors, to simulate the continuous light and shade of colors and their gradient changes. Therefore, the biggest advantage of digital printing technology is: color Rich and sophisticated, no additional plate making (spot color plate) is required, and it has various advantages such as short production time and high customization.

The biggest disadvantage of digital printing technology is that it costs a lot to invest in digital printing equipment up front. Well, in addition, current digital printing equipment is not suitable for all fabrics and colors. The reason is that it is difficult to master the fabric concentration, fabric type and fabric characteristics. Especially for dark fabrics or denim materials, the background color of the fabric is often too high. Dark, resulting in the printed color pattern not being able to develop on the fabric. Traditionally, the area of the color pattern to be dyed and printed on the dark fabric needs to be removed (faded) using color-discharging technology, and then the color pattern is dyed and printed on the fabric. This is the color extraction area, so that color patterns with high color rendering effects can be printed on the dark parts.

However, although the above-mentioned color-discharging technology can achieve color patterns with high color rendering effects on dark fabrics, it also causes many environmental pollution concerns. Color-discharging (also known as color stripping) technology uses oxidants or reducing agents. Chemicals such as these can reduce or oxidize dark dyes on dark fabrics, thereby producing a fading (erasing) effect. In order to remove the above chemicals, repeated washing and drying operations are required, otherwise residual Chemical agents can easily cause severe allergic reactions and other adverse reactions on human skin. The dyeing and printing technology can be said to be a high water consumption and high pollution dyeing and printing technology.

Therefore, it is the subject of the present invention to effectively eliminate the high water consumption and high pollution discharge technology and to dye and print color patterns with high color reproduction on dark cloth.

The main purpose of the present invention is to provide a method for making a spot color plate with high color rendering that can be used on dark-colored fabrics. It is based on separating a finished pattern into a plurality of corresponding grayscale files based on a plurality of color plates. According to the dark color According to the different specifications of the cloth, at least 70% of the density and inversion compensation adjustments are made to these grayscale files to obtain each spot color file, so that the colors of the finished pattern can be adjusted according to the background color density and fabric specifications of the dark cloth. The corresponding conditions determine the corresponding density of the color plate, so that the dark cloth can be dyed and printed to produce a pattern with high color reproduction.

In order to achieve the above object, the present invention provides a high color rendering device for dark cloth. The special spot color plate production method allows the printed target fabric to be dyed and printed with high color reproduction color patterns. The method includes: Step 1: The target fabric is printed according to the color of each color plate ((C, M, Y, K). Color plate) or (C, M, Y, K, O, G six-color plate)) respectively print the density levels from 1% to 100% in at least four directions, and then obtain the concentration curve of the highest and lowest concentration values of each color plate. Scope; Step 2: Select a color finished artwork and separate it into four or six first group grayscale files according to the four-color version or the six-color version; Step 3: Divide the aforementioned four or six first group grayscale files Based on the concentration curve ranges of the highest and lowest concentration values of each color plate obtained in step 1, take 70% of the concentration curve range as the maximum concentration value and set the concentration to the second set of grayscale files; Step 4: According to the concentration curve obtained in step 1 The straight line connecting the density curve range of 1% to 70% of each color plate is the standard line, and then the difference between the density curve and the standard line is used as the reverse density compensation value of the second grayscale file of each color plate, and then the spot color version is completed. The target fabric can be dyed and printed with high color reproduction of the finished artwork.

According to the main characteristics mentioned above, the background color of the target fabric defined in the present invention is in the color range from dark gray RGB (110,110,110) to black RGB (0,0,0).

C:Concentration level

S1~S4: steps

L1: standard line

L2: reverse concentration compensation value

Figure 1 is a schematic diagram of the density level of the method for making a spot color plate with high color rendering applied to dark fabrics according to the present invention. It shows that the target fabric obtained in step 1 is printed with a density level of 1% to 100% of a color.

Figure 2 is a schematic flow chart of the production method of a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

Figure 3 is a graph showing the concentration curve of the black plate using the method for making a spot color plate with high color rendering properties of the present invention applied to dark cloth.

Figure 4 is a graph showing the concentration curve of the yellow plate using the method for making a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

Figure 5 is a graph showing the concentration curve of the magenta version of the method for making a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

Figure 6 is a graph showing the concentration curve of the cyan plate using the method for making a spot color plate with high color rendering properties of the present invention applied to dark cloth.

Figure 7 is a graph showing the concentration curve of the orange version of the method for making a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

Figure 8 is a graph showing the concentration curve of the green version of the method for making a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

In order to achieve the above-mentioned objects and effects, the technical means and structures adopted by the present invention are described in detail below with respect to the preferred embodiments of the present invention, so as to facilitate a complete understanding.

Please refer to Figures 1 and 2. Figure 1 is a schematic diagram of the density level of the method for making a spot color plate with high color rendering properties applied to dark cloth according to the present invention. It shows that the target fabric obtained in step 1 will be printed with one color. Concentration levels from 1% to 100% are available. Figure 2 is a schematic flow chart of the production method of a spot color plate with high color rendering properties applied to dark cloth according to the present invention.

In order to achieve the above object, the present invention provides a method for making a spot color plate with high color rendering for dark-colored fabrics, so that the target fabric to be printed does not need to go through the color removal process, and can be used for color separation plate making using traditional screen printing technology. Coupled with the principle of color stacking and half-tone color mixing in digital printing, it can be directly For dyeing and printing color patterns with high color reproduction, the target fabric defined in the present invention is defined as having a background color ranging from dark gray RGB (110, 110, 110) to black RGB (0, 0, 0), which will be explained here.

The method for making a spot color plate with high color rendering for dark fabrics of the present invention at least includes: Step S1: Make a target fabric according to the color of each color plate (C (cyan), M (magenta), Y (yellow) , K (black) four-color version or C (cyan), M (magenta), Y (yellow), K (black), O (orange), G (green) six-color version) printed at least four times respectively Concentration level C from 1% to 100% in each direction (as shown in Figure 1), obtain the concentration curve range of the highest and lowest concentration values of each color on the target fabric (as shown in Figures 3 to 8); Step S2: Select a color finished artwork file to scan or load the image file into computer imaging software to modify and adjust or edit it into a finished pattern, according to the four-color version (C, M, Y, K) or the six-color version (C , M, Y, K, O, G) respectively separate the finished pattern into four or six first group grayscale files (as shown in Figure 1); Step S3: Divide the aforementioned four or six first group The grayscale files are based on the concentration curve ranges of the highest and lowest concentration values of each color version obtained in step S1, and 70% of the concentration curve range is taken as the maximum concentration value to set the concentration into the second set of grayscale files; Step S4: Follow the steps The straight line connecting the concentration curve range of 1% to 70% of each color plate obtained by S1 is the standard line L1 (shown as a dotted line in the figure), and then the difference between the concentration curve and the standard line is used as the reverse of the second grayscale file of each color plate. The density compensation value L2 (shown as a thin chain line in the picture) is then used to complete the spot color version (as shown in pictures 3 to 8), so that the finished artwork with high color reproduction can be dyed and printed on the target fabric to be printed; in this way Therefore, the present invention can effectively use the overlapping and half-tone color mixing principles of digital printing technology on the basis of the color separation plate making of traditional screen printing technology to ensure the color reproducibility of fabric printing. The subject of study.

The above-mentioned embodiments are used to illustrate one of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention. Anyone skilled in the art can make some modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the appended patent application scope.

S1~S4: steps

Claims (2)

A method for making a spot color plate with high color rendering properties applied to dark-colored fabrics, so that color patterns with high color reproduction can be dyed and printed on the printed target fabric. The method includes: Step 1: Make the target fabric according to each color plate Colors ((C, M, Y, K four-color version) or (C, M, Y, K, O, G six-color version)) are printed with concentration levels from 1% to 100% in at least four directions, and then Obtain the concentration curve range of the highest and lowest concentration values of these color plates; Step 2: Select a color finished artwork and separate it into four or six first sets of grayscale files according to the four-color version or the six-color version; Step 3 : Based on the concentration curve ranges of the highest and lowest concentration values of each color version obtained in step 1, take the 70% area of the concentration curve range as the maximum concentration value and set the concentration to the second Assemble grayscale files; Step 4: The straight line connecting 1% to 70% of the concentration curve range of each color version obtained in step 1 is the standard line, and the difference between the concentration curve and the standard line is used as the inverse of the second grayscale file of each color version. Compensate the value to the density to achieve a high color rendering spot color version. The method for making a spot color plate with high color rendering for dark fabrics as described in claim 1, wherein the background color of the target fabric is at least dark gray RGB (110,110,110) to black RGB (0,0,0) Range interval.

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