CN113306289A - Printing color correction method for matte film surface - Google Patents
Printing color correction method for matte film surface Download PDFInfo
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F23/00—Devices for treating the surfaces of sheets, webs, or other articles in connection with printing
- B41F23/08—Print finishing devices, e.g. for glossing prints
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F33/00—Indicating, counting, warning, control or safety devices
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B41—PRINTING; LINING MACHINES; TYPEWRITERS; STAMPS
- B41F—PRINTING MACHINES OR PRESSES
- B41F33/00—Indicating, counting, warning, control or safety devices
- B41F33/0036—Devices for scanning or checking the printed matter for quality control
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Abstract
The invention relates to the technical field of color correction, in particular to a method for correcting printing colors on the surface of a matte film, which comprises the following steps: pre-printing pretreatment, namely setting initial preset conditions before printing, controlling CTP dot tolerance and determining whether influence parameters are in normal values; and color correction of the surface process of the matte film, wherein the color correction comprises the following steps: determining the optimal density of the four-color ink in a dry state, and calculating the optimal printing wet density of the four colors in the printing process; acquiring a basic state of the printing machine after the printing machine reaches corresponding technical parameters, and ensuring the state of the printing machine after the target density on the spot calibrated by an ink test is reached; verifying standard parameters of NPDC and gray balance; performing a film covering process, and printing and sample reserving according to the target density determined in the step S2 correction process; the invention compares the color matching degree between the printed sample and the digital sample, and solves the problems of large color difference of printed products before and after the existing dummy film and high sample making loss rate.
Description
Technical Field
The invention relates to the technical field of color correction, in particular to a printing color correction method for the surface of a matte film.
Background
The film coating process is one of common processes for finishing the surface of a printed matter, the touch feeling and the visual effect of the printed matter can be enhanced by coating the matte film on the surface, and the protection performances of the product such as abrasion resistance, dirt resistance, water resistance, oil resistance and the like are greatly improved. Therefore, in recent years, the matte film coating process is frequently applied to packaging products, books and magazines, and covers of specifications. The international standard for offset printing colors is mainly for prints without any post-press surface finishing process, and color management after matte lamination is temporarily blank. The colors of the printed matters before and after the matte film have large differences, under the condition that no standard can be met, enterprises need to flexibly apply a color management method, effectively pre-judge the color change of the film, formulate a set of matte film process color management working flow according with the self condition, improve the customer satisfaction, reduce the proofing loss and have great significance to production practice.
With the development of multimedia technology and color printing technology, the application of color images has become an increasingly popular research field. Because the color image has richer connotation and stronger expressive force than characters, sounds and gray level images, the information can be more accurately transmitted, and better visual effect can be achieved
The color correction technology is a key technology and difficulty of color management, and the difficulty is that the technology not only maps all colors in a primary color domain to a target color domain, but also keeps the visual effect of an original image as much as possible. A good mapping algorithm will help to improve the color management capabilities. At present, the research on color correction technology has been greatly advanced, but due to the complexity of the technology, the related field is wide, and new problems are continuously generated.
Disclosure of Invention
Aiming at the defects of the prior art, the invention discloses a printing color correction method for the surface of a dummy film, which is used for solving the problems of large color difference of printed products before and after the existing dummy film and high proofing loss rate;
the invention is realized by the following technical scheme:
the invention discloses a printing color correction method for the surface of a matte film, which is used for performing color correction on the matte film coated on the surface of a printed matter; the color correction method includes the steps of:
s1, preprocessing before printing;
wherein the pre-treatment comprises the steps of: setting initial preset conditions before printing, controlling CTP dot tolerance, and determining whether influence parameters are in normal values;
s2, color correction of the matte film surface process;
wherein the color correction comprises the steps of:
s201, testing and selecting the ink, determining the optimal density of the four-color ink in a dry state, and calculating the optimal printing wet density of the four colors in the printing process;
s202, acquiring a basic state of the printer after the printer reaches corresponding technical parameters, adjusting an ink key of the printer, checking the TVI of CMYK colors after the target density on the spot calibrated by an ink test is reached, and ensuring the state of the printer;
s203, verifying standard parameters of NPDC and gray balance by using the correction printing of G7;
s3, performing a film laminating process, and printing and sample reserving according to the target density determined in the step S2 correction process;
and S4, comparing the color matching degree between the printed sample and the digital sample under a standard light source.
Preferably, the initial preset conditions are as follows: the temperature and humidity of a workshop, the developing time, the temperature and the conductivity of the developing solution are set, and the pressure of the water ink roller is checked and adjusted.
Preferably, the step of checking and adjusting the pressure of the water roller is: the pressure between four forme inking rollers, the forme water roller and the forme cylinder of each color group is checked, and the width of the ink pressing line between the four forme inking rollers, the forme water roller and the forme is measured by using a special measuring ruler.
Preferably, the influencing parameters are: the cleanliness of fountain solution in a water tank, the temperature of the fountain solution, the alcohol proportion, the PH value and the conductivity; and when the cleanness of the fountain solution is not in a normal state, cleaning the water tank and replacing with new fountain solution.
Preferably, the determining the optimal density values of the four-color ink comprises the following steps: scanning a color ribbon at the tail of the plate by using a scanner, recording the printing wet density, and marking a scanning number on a printed sheet; after the sample sheet is fully dried, scanning the tail color band of the sample sheet again, and selecting a target density according to a color target, wherein the target density is a four-primary-color density optimal matching value and a wet density corresponding to the four-primary-color density optimal matching value.
Preferably, the step of determining the state of the printing press comprises: respectively collecting data sets of a left P2P51 chart, a right P2P51 chart and a TC1617 chart, and generating an ICC profile; resetting CMYK target density according to the result of the ink test, scanning a film-coated front plate tail color band by the scanner, printing a sample sheet after the density reaches the standard, and reserving the sample for later use; selecting a sample sheet to be covered with a matte film, cutting the left and right sides of the P2P according to cutting lines, connecting X-Rite iSis with Curve4 software to automatically read data and calculate a printing correction Curve.
Preferably, the step of verifying the standard parameters is: RIP is carried out again on the correction curve and the linearization curve, a printing plate is output, and whether the output printing plate mesh points are accurate or not is measured and checked; and (3) keeping the target density of the linear plate to be consistent for printing, ensuring that CMYKRGB is in accordance with the standard on the spot, paying attention to gray balance expression of highlight contrast, highlight range and shadow contrast, and keeping the printing sample sheet for later use after the data reach the standard.
Preferably, the sample sheet is selected, the P2P51 and the TC1617 on the sample sheet are cut, a chart is measured by the Curve4 software, and data are stored; and selecting the dummy film again, cutting the P2P51 and the TC1617 on the sample after film covering, measuring chart saved data by using the Curve4 software, and analyzing the data.
Preferably, the temperature and humidity of the environment of the film covering workshop are controlled in the film covering technological process, the film covering temperature, the film covering pressure and the film covering speed are subjected to parameter setting according to the film covering requirements, and the film covering direction is kept consistent.
Preferably, the step of comparing the color matching degrees in step S4 specifically comprises: analyzing and comparing color scanning data of the dummy film front and back samples, finding out the change rule of the data after film coating, correcting data groups of the dummy film front and back samples by using G7, respectively generating ICC profile files, and displaying and comparing the ICC profile files in ColorThiink software.
The invention has the beneficial effects that:
1. the method emphasizes the advantages of G7 calibration result guidance, realization of shared gray balance appearance by different materials, easiness in operation, low cost and the like, and can quickly solve the urgent need between a seal enterprise and a client. The color imaging system is applied to various color imaging systems and meets the diversified product requirements brought by the current personalized market. The printing color is corrected by using a G7 method, surface finishing is carried out by applying a matte coating process, and the data difference and the change of the image color before and after film coating are contrastively analyzed, so that a matte printing color characteristic file is established, and the matte printing color characteristic file can be used for correcting a digital proofing color standard and visually verifying the color accuracy of a printer digital proofing simulation printer after film coating. Standardizing and digitizing the whole operation flow, and checking the standardization of each link so as to accurately and efficiently solve the problem of color control of the matte process.
2. After color correction, the printed sample sheet after film coating and the dummy film standard digital sample sheet have high level and color matching degree, can meet the requirements of most customers, and can reach the standard by finely adjusting a printing correction curve for the customers with higher color detail requirements. According to the invention, the printing correction curve is set to take G7 gray balance as a target, and is obtained by measuring and calculating the dummy film coated sample, so that the Grayscale gray balance module does not reach the standard before G7 corrects the printed sample film to be coated, but the Grayscale module reaches the standard after the printing film is coated, and finally the target of the dummy film coating process for sharing the gray balance appearance is realized.
3. The invention analyzes and contrasts the color change before and after the dummy film, collects the color data after the dummy film is covered as the color target, and takes the influence of the dummy film on the color into consideration, thereby improving the color predictability in the printing process and improving the printing efficiency.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly described below, it is obvious that the drawings in the following description are only some embodiments of the present invention, and for those skilled in the art, other drawings can be obtained according to the drawings without creative efforts.
FIG. 1 is a schematic flow diagram of the present invention;
fig. 2 is a schematic flow chart of the color correction according to the present invention.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
Example 1
The embodiment mainly corrects the printing color by using a G7 method, performs surface finishing by using a matte film coating process, contrasts and analyzes the data difference and change of the image color before and after film coating, further establishes a matte film printing color characteristic file, can be used for correcting a digital proofing color standard, and visually verifies the accuracy of the color of a printer after a digital sample simulates a printer film coating. Standardizing and digitizing the whole operation flow, and checking the standardization of each link so as to accurately and efficiently solve the problem of color control of the matte process.
The temperature and the humidity of the environment of a film laminating workshop are controlled in the film laminating process, the film laminating temperature, the film laminating pressure and the film laminating speed are subjected to parameter setting according to the film laminating requirement, the film laminating direction is kept consistent, and the good film laminating effect and the repeatability are ensured as much as possible. In addition, ensuring the uniformity of the materials is of great significance to the stability and control of subsequent colors. The invention adopts the pre-coated matte film, the film coating temperature is the first factor, the adhesive on the pre-coated matte film is hot melt adhesive, the temperature determines the fusion state of the adhesive, and the penetration and diffusion capability of hot melt adhesive molecules to the contact surfaces of ink, paper and the like on printed matters are also determined. It should be additionally noted that the highest possible temperature and pressure can help to increase the bonding strength, but if the temperature and pressure are too high, the film will shrink, the surface of the product will shine, foam, and even the semi-finished product will wrinkle. In this embodiment, the temperature is set at 100-115 deg.C, the pressure is 8-11pa, and the speed is stabilized at 70 m/min.
The measuring instruments required to be used in different links in the working process are different in brand and model, so that data interaction and inter-station difference management and control are particularly important, and the corrected measuring instruments and the unified measuring conditions provide basic guarantee for smooth follow-up tests.
(1) The measuring instrument is as follows: different measuring equipment used in the inspection ensures that the difference between the instruments is within a reasonable range, and avoids the influence on data and calculation results due to measurement errors.
(2) Measurement conditions were as follows: the measurement conditions are set with reference to the offset printing international standard ISO 12647-2. M1 measurement mode, D50 light source, 2-degree view angle and color difference delta E00 formula.
(3) Color target: the printing data reference target before lamination is GRACoL2013_ CRPC6 in reference to offset printing international standards ISO12647-2 and ISO/PAS 15339.
Referring to fig. 1, the color correction method includes the following steps:
s1, preprocessing before printing;
in step S1, setting initial preset conditions before printing, controlling CTP dot tolerance, and determining whether the influencing parameters are normal values;
the initial preset conditions are as follows: the temperature and humidity of a workshop, the developing time, the temperature and the conductivity of the developing solution are set, so that the stability of publishing points is facilitated, and the pressure of the ink roller is checked and adjusted. After the printing plate is output, the size of the dots on the printing plate measuring and controlling strip is checked by using a printing plate measuring instrument, and the dot tolerance is recommended to be controlled within +/-0.5%, which is not difficult for a thermosensitive CTP.
Wherein the step of checking and adjusting the pressure of the water roller is: the pressure between four forme inking rollers, the forme water roller and the forme cylinder of each color group is checked, and the width of the ink pressing line between the four forme inking rollers, the forme water roller and the forme is measured by using a special measuring ruler.
The pressure adjustment of the ink roller is one of the key factors for obtaining good ink balance, is also an important basis for avoiding the front and back of a printed product and keeping the uniformity of a layout, and is important for stabilizing the printing machine.
The influence parameters are as follows: the cleanliness of fountain solution in a water tank, the temperature of the fountain solution, the alcohol proportion, the PH value and the conductivity; and when the cleanness of the fountain solution is not in a normal state, cleaning the water tank and replacing with new fountain solution.
S2, color correction of the matte film surface process;
referring to fig. 2, the color correction in step S2 includes the following steps:
s201, testing and selecting the ink, determining the optimal density of the four-color ink in a dry state, and calculating the optimal printing wet density of the four colors in the printing process;
wherein the step of determining the optimal density values of the four-color ink comprises the following steps: scanning a color band at the tail of the plate by using an X-Rite ITX2 scanner, recording the printing wet density, and marking a scanning number on a printed sheet for subsequent selection and pursuit; after the sample sheet is fully dried, the tail color band of the sample sheet plate is scanned again, and the target density is selected according to CMYKRGB color targets in GRACoL2013_ CRPC6, wherein the target density is the four-primary-color density optimal matching value and the wet density corresponding to the four-primary-color density optimal matching value.
In other embodiments, the printing machine is provided with the on-line glazing unit, and the printing machine is printed with the base oil, so that the influence caused by the ink fading phenomenon is reduced as much as possible, the ink is stable in performance, and the data acquisition is facilitated.
S202, acquiring a basic state of the printer after the printer reaches corresponding technical parameters, adjusting an ink key of the printer, checking the TVI of CMYK colors after the target density on the spot calibrated by an ink test is reached, and ensuring the state of the printer;
the linear printing stage of this embodiment does not require NPDC and gray balance, but should achieve color uniformity of the entire proof layout as much as possible, avoid the phenomenon of inconsistency of P2P calibration curves in different areas of the same layout, further check and ensure color consistency of the proof before and after printing, and eliminate the occurrence of printing faults such as color change, color jump, ghost images, ink sticks, misregistration, dark front and light back.
The step of determining the state of the printing press comprises the following steps: the method comprises the steps of respectively collecting a left P2P51 chart and a right P2P51 chart to balance the uniformity of printed sheets and a data set of a TC1617 chart, generating an ICC profile, and transverse and longitudinal four-color solid and flat screen gray balance control bars, wherein the ICC profile is used for detecting the solid density and the flat screen state of different printing areas of a printing surface and ensuring the color uniformity of the printing surface; resetting CMYK target density according to the result of the ink test, scanning a film-coated front plate and a film-coated tail color band by the scanner, keeping the uniformity of a printing layout, printing 50 sample sheets after the density reaches the standard, and reserving the sample for later use; selecting three sample sheets to be covered with a matte film, cutting the left and right sides of the P2P according to cutting lines, connecting X-Rite iSis with Curve4 software to automatically read data and calculate a printing correction Curve.
S203, verifying the standard parameters of NPDC and gray balance by using the proofreading of G7.
The standard parameter verification method comprises the following steps: RIP is carried out again on the correction curve and the linearization curve, a printing plate is output, and whether the output printing plate mesh points are accurate or not is measured and checked; and (3) keeping the target density of the linear plate to be consistent for printing, ensuring that CMYKRGB is in accordance with the standard on the spot, paying attention to gray balance expression of bright tone contrast, highlight range and dark tone contrast, and keeping 50 printing sample sheets for standby after the data reach the standard. Selecting the three samples, cutting the P2P51 and the TC1617 on the three samples, measuring a chart by using the Curve4 software, and storing data; and selecting three sample sheets again, coating a dummy film on the three sample sheets, cutting the P2P51 and the TC1617 on the three sample sheets after coating, measuring a chart by using the Curve4 software, storing data, and analyzing the data.
In this embodiment, the Curve4 software is used for comparative analysis, and the Curve4 is a multifunctional software, and is used for verifying whether the printed matter meets the requirements of different grades of G7, correcting the state of the printing press, and performing higher-requirement data analysis and adjustment by professional colorists.
S3, performing a film laminating process, and printing and sample reserving according to the target density determined in the step S2 correction process;
and S4, comparing the color matching degree between the printed sample and the digital sample under a standard light source.
The step of comparing the color matching degrees in step S4 specifically includes: analyzing and comparing color scanning data of the dummy film front and back samples, finding out the change rule of the data after film coating, correcting data groups of the dummy film front and back samples by using G7, respectively generating ICC profile files, and displaying and comparing the ICC profile files in ColorThiink software.
The method emphasizes the advantages of G7 calibration result guidance, realization of shared gray balance appearance by different materials, easiness in operation, low cost and the like, and can quickly solve the urgent need between a seal enterprise and a client. The color imaging system is applied to various color imaging systems and meets the diversified product requirements brought by the current personalized market. The printing color is corrected by using a G7 method, surface finishing is carried out by applying a matte coating process, and the data difference and the change of the image color before and after film coating are contrastively analyzed, so that a matte printing color characteristic file is established, and the matte printing color characteristic file can be used for correcting a digital proofing color standard and visually verifying the color accuracy of a printer digital proofing simulation printer after film coating. Standardizing and digitizing the whole operation flow, and checking the standardization of each link so as to accurately and efficiently solve the problem of color control of the matte process.
The invention analyzes and contrasts the color change before and after the dummy film, collects the color data after the dummy film is covered as the color target, and takes the influence of the dummy film on the color into consideration, thereby improving the color predictability in the printing process and improving the printing efficiency.
Example 2
The embodiment discloses a method for correcting the printing color of the surface of the matte film in embodiment 1, in addition, in the embodiment, samples are respectively visually compared under a standard light source, and clothes worn by a standard observer are mainly black, white and grey, so that the observation result is prevented from being influenced by colored clothes. The results of the visual comparison by the observer are well documented and summarized analytically.
The color viewing condition of visual contrast is that different light sources have different influences on colors because printed matters are easy to generate metamerism. According to ISO 3664, in the print reproduction segment, there are several key elements to ensure stable and consistent viewing conditions: spectral power distribution of the illumination source; the luminous intensity and uniformity of the illumination source; viewing environmental conditions (including both viewing environment and lighting environment content); stability of the lighting environment.
The D50 standard light source needs to satisfy the following points: the brightness of the printed sheets was observed to be 2000 ± 500 lumens (Lux); luminance uniformity, 75% (relative to center point) 1 square meter; the color temperature of a standard light source is 5000K (+ -500K); a standard light source Color Rendering Index (CRI) of 90 or more; MI metamerism index is less than 1.
The visual contrast result shows that the difference of the colors of the sample sheets before and after the matte coating is larger, and the difference is mainly reflected as follows: matte films can change overall print color (substrate, ink field, overprint and neutral gray); the matte film can reduce the brightness value L of a printing stock and also can reduce the color saturation; the matte film enables the darkest color tone to be lighter, and enables the highlight light color tone to be darker; the matte film will compress the dynamic range (distance between the darkest black and brightest white).
Example 3
In addition to the method for correcting the printing color of the surface of the dummy film in embodiment 2, the present embodiment also provides a color management process for standardizing the dummy film process, where the color management process is a process of data acquisition and color restoration, and the stability of each link is very important for the final verification result, so that all the links must be strictly operated according to standardization and normalization, and thus the adopted data is reliable and repeatable. This is also a key and difficult point in color management.
The method comprises the following steps:
s101, after receiving an original file of a client, carrying out standardized inspection on the file. Ensuring that all parameters of the file meet the requirements of all links before printing, printing and after printing;
s102, for files which need to be covered with a dummy film and have higher color requirements in the subsequent process, displaying the files on a screen by using a dummy film standard ICC characteristic file by using a screen soft proofing function before a digital proofing link, and previewing the color effect of a final product;
s103, printing a digital sample according to the newly established dummy film standard, detecting whether the data is qualified, and comparing the digital sample with the client target color draft under a standard light source. If necessary, the color curve of the document needs to be adjusted in advance until the digital sample is close to the target color draft. The adjustment after the printing and the machine is operated is optimized to the front of the machine, so that the time and the capacity waste of the machine operation adjustment are greatly saved, and the efficiency is improved;
s104, outputting the printing plate before printing, and detecting and ensuring the accuracy of printing plate mesh points;
s105, printing on a machine to ensure that the printing state is normal, adjusting ink keys to keep the color uniformity of printed sheets according to the printing target density calibrated by ink test, selecting sample sheets to coat a matte film after the printed sheets reach the standard, and detecting the accuracy of gray balance;
and S106, subjectively and visually comparing the difference between the printing color and the target color draft, and if further improvement is needed, finely adjusting and modifying the color correction curve again to further match the sample sheet with the target color draft.
The matte film process has a large influence on the printing color, and the same color standard is not suitable for evaluating and guiding the printing. The color change before and after the dummy film is analyzed and contrasted, the color data after the dummy film is covered is collected as a color target, the influence of the dummy film on the color is taken into consideration, the color predictability in the printing process can be improved, and the printing efficiency is improved. Color management is closely related to each link of production, and color management can help enterprises to efficiently solve color problems.
The above examples are only intended to illustrate the technical solution of the present invention, but not to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some technical features may be equivalently replaced; and such modifications or substitutions do not depart from the spirit and scope of the corresponding technical solutions of the embodiments of the present invention.
Claims (10)
1. A printing color correction method for the surface of a matte film is characterized by comprising the following steps: the color correction device is used for performing color correction on the matte film coated on the surface of a printed matter; the color correction method includes the steps of:
s1, preprocessing before printing;
wherein the pre-treatment comprises the steps of: setting initial preset conditions before printing, controlling CTP dot tolerance, and determining whether influence parameters are in normal values;
s2, color correction of the matte film surface process;
wherein the color correction comprises the steps of:
s201, testing and selecting the ink, determining the optimal density of the four-color ink in a dry state, and calculating the optimal printing wet density of the four colors in the printing process;
s202, acquiring a basic state of the printer after the printer reaches corresponding technical parameters, adjusting an ink key of the printer, checking the TVI of CMYK colors after the target density on the spot calibrated by an ink test is reached, and ensuring the state of the printer;
s203, verifying standard parameters of NPDC and gray balance by using the correction printing of G7;
s3, performing a film laminating process, and printing and sample reserving according to the target density determined in the step S2 correction process;
and S4, comparing the color matching degree between the printed sample and the digital sample under a standard light source.
2. The method for correcting the printing color of the surface of the matte film according to claim 1, wherein: the initial preset conditions are as follows: the temperature and humidity of a workshop, the developing time, the temperature and the conductivity of the developing solution are set, and the pressure of the water ink roller is checked and adjusted.
3. The method for correcting the printing color of the surface of the matte film according to claim 2, wherein: wherein the step of checking and adjusting the pressure of the water roller is: the pressure between four forme inking rollers, the forme water roller and the forme cylinder of each color group is checked, and the width of the ink pressing line between the four forme inking rollers, the forme water roller and the forme is measured by using a special measuring ruler.
4. The method for correcting the printing color of the surface of the matte film according to claim 1, wherein: the influence parameters are as follows: the cleanliness of fountain solution in a water tank, the temperature of the fountain solution, the alcohol proportion, the PH value and the conductivity; and when the cleanness of the fountain solution is not in a normal state, cleaning the water tank and replacing with new fountain solution.
5. The method for correcting the printing color of the surface of the matte film according to claim 1, wherein: wherein the step of determining the optimal density values of the four-color ink comprises the following steps: scanning a color ribbon at the tail of the plate by using a scanner, recording the printing wet density, and marking a scanning number on a printed sheet; after the sample sheet is fully dried, scanning the tail color band of the sample sheet again, and selecting a target density according to a color target, wherein the target density is a four-primary-color density optimal matching value and a wet density corresponding to the four-primary-color density optimal matching value.
6. The method for correcting the printing color of the surface of the matte film according to claim 5, wherein: the step of determining the state of the printing press comprises the following steps: respectively collecting data sets of a left P2P51 chart, a right P2P51 chart and a TC1617 chart, and generating an ICC profile; resetting CMYK target density according to the result of the ink test, scanning a film-coated front plate tail color band by the scanner, printing a sample sheet after the density reaches the standard, and reserving the sample for later use; selecting a sample sheet, coating a dummy film, cutting the left and right P2P according to cutting lines, connecting X-RiteiSis with Curve4 software, automatically reading data, and calculating a printing correction Curve.
7. The method for correcting the printing color of the surface of the matte film according to claim 6, wherein: the standard parameter verification method comprises the following steps: RIP is carried out again on the correction curve and the linearization curve, a printing plate is output, and whether the output printing plate mesh points are accurate or not is measured and checked; and (3) keeping the target density of the linear plate to be consistent for printing, ensuring that CMYKRGB is in accordance with the standard on the spot, paying attention to gray balance expression of highlight contrast, highlight range and shadow contrast, and keeping the printing sample sheet for later use after the data reach the standard.
8. The method for correcting the printing color of the surface of the matte film according to claim 7, wherein: selecting the sample sheet, cutting the P2P51 and the TC1617 on the sample sheet, measuring a chart by using the Curve4 software, and storing data; and selecting the dummy film again, cutting the P2P51 and the TC1617 on the sample after film covering, measuring chart saved data by using the Curve4 software, and analyzing the data.
9. The method for correcting the printing color of the surface of the matte film according to claim 1, wherein: and in the film covering process, the temperature and the humidity of the environment of a film covering workshop are controlled, the film covering temperature, the film covering pressure and the film covering speed are subjected to parameter setting according to the film covering requirement, and the film covering direction is kept consistent.
10. The method for correcting the printing color of the surface of the matte film according to claim 1, wherein: the step of comparing the color matching degrees in step S4 specifically includes: analyzing and comparing color scanning data of the dummy film front and back samples, finding out the change rule of the data after film coating, correcting data groups of the dummy film front and back samples by using G7, respectively generating ICC profile files, and displaying and comparing the ICC profile files in ColorThiink software.
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Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114638786A (en) * | 2022-02-21 | 2022-06-17 | 杭州印鸽科技有限公司 | Picture printing effect simulation system and color matching method for different processes |
| CN116552130A (en) * | 2022-01-27 | 2023-08-08 | 东莞当纳利印刷有限公司 | Color management method and device among multiple devices and non-transitory computer storage medium |
| CN116552130B (en) * | 2022-01-27 | 2024-06-07 | 东莞当纳利印刷有限公司 | Color management method and device among multiple devices and non-transitory computer storage medium |
Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104943354A (en) * | 2015-07-13 | 2015-09-30 | 东莞当纳利印刷有限公司 | Color management method and device for laminated printed products |
| CN105774190A (en) * | 2016-03-07 | 2016-07-20 | 安庆市达东电子科技有限公司 | Device for correcting hue before and after printing laminating |
| CN107042689A (en) * | 2017-04-24 | 2017-08-15 | 北京奇良海德印刷股份有限公司 | A kind of printing color quality detecting method |
| CN110481154A (en) * | 2019-08-15 | 2019-11-22 | 北京雅昌艺术印刷有限公司 | A kind of control method and control system of the misalignment of overlay film printed matter |
| CN111703198A (en) * | 2020-06-12 | 2020-09-25 | 深圳职业技术学院 | Printing method, printing device and printing system |
| CN112537148A (en) * | 2020-09-30 | 2021-03-23 | 湖北合信智能包装科技有限公司 | Method for matching colors of digital printing and flexography |
-
2021
- 2021-06-21 CN CN202110685063.5A patent/CN113306289A/en active Pending
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104943354A (en) * | 2015-07-13 | 2015-09-30 | 东莞当纳利印刷有限公司 | Color management method and device for laminated printed products |
| CN105774190A (en) * | 2016-03-07 | 2016-07-20 | 安庆市达东电子科技有限公司 | Device for correcting hue before and after printing laminating |
| CN107042689A (en) * | 2017-04-24 | 2017-08-15 | 北京奇良海德印刷股份有限公司 | A kind of printing color quality detecting method |
| CN110481154A (en) * | 2019-08-15 | 2019-11-22 | 北京雅昌艺术印刷有限公司 | A kind of control method and control system of the misalignment of overlay film printed matter |
| CN111703198A (en) * | 2020-06-12 | 2020-09-25 | 深圳职业技术学院 | Printing method, printing device and printing system |
| CN112537148A (en) * | 2020-09-30 | 2021-03-23 | 湖北合信智能包装科技有限公司 | Method for matching colors of digital printing and flexography |
Non-Patent Citations (1)
| Title |
|---|
| 许俊龙: "覆膜后的色彩管理", 《今日印刷》 * |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN116552130A (en) * | 2022-01-27 | 2023-08-08 | 东莞当纳利印刷有限公司 | Color management method and device among multiple devices and non-transitory computer storage medium |
| CN116552130B (en) * | 2022-01-27 | 2024-06-07 | 东莞当纳利印刷有限公司 | Color management method and device among multiple devices and non-transitory computer storage medium |
| CN114638786A (en) * | 2022-02-21 | 2022-06-17 | 杭州印鸽科技有限公司 | Picture printing effect simulation system and color matching method for different processes |
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