Graphic technology—Process control for the production of half-tone colour separations,proofs and production prints—Part 6:Flexographic printing
Some standard content:
ICS37.100.01
National Standard of the People's Republic of China
GB/T17934.6—2014Www.bzxZ.net
Printing technology
Process control for the production of half-tone colour separations, proofs and production of printed products Part 6: Flexographic printing
Graphic technologyProcess control for the production of half-tone colour separations, proofs and production prints-Part 6:Flexographic printing
(ISO 12647-6:2006, MOD)
Released on December 31, 2014
General Administration of Quality Supervision, Inspection and Quarantine of the People's Republic of China Administration of Standardization of the People's Republic of China
Implementation on July 1, 2015
Normative references
Terms and definitions
Technical requirements
4.2 Data files, color separations and printing plates
4.3 Proofing sheets or prints
5 Test method: Tone values and tone added values of printed products...6 Reporting of printing conditions
Appendix A (informative) Structural changes between this part and ISO 12647-6:2006Appendix B (informative) Technical differences between this part and ISO 12647-6:2006 Appendix C (Informative Appendix)
Control range of solid reflection density value of printing secondary primary color Appendix D (Informative Appendix) Comparison table of centimeter and inch screen number range Appendix E (Informative Appendix)
References
Combination of gray balance color block gradation value
GB/T17934.6—2014
GB/T17934 "Printing Technology Screen" "Process control of halftone color separations, samples and printed products" consists of the following 8 parts: Part 1: Parameters and test methods; Part 2: Offset printing; Part 3: Coldset ink offset printing of newsprint; Part 4: Gravure printing; Part 5: Screen printing; Part 6: Flexographic printing; Part 7: Digital proofing; Part 8: Digital printing. This part is Part 6 of GB/T 17934. This part was drafted according to the rules given in GB/T 1.1-2009. This part was prepared on the basis of ISO 12647-6:2006 "Printing technology - Process control of halftone color separations, samples and printed products - Part 6: Flexographic printing" by redrafting method, and the consistency with ISO 12647-6:2006 is modified and adopted. Compared with ISO12647-6:2006, this part has many structural adjustments. Appendix A lists the chapter and article numbers of this part and ISO12647-6:2C06.
There are technical differences between this part and ISO12647-6:2006. The technical clauses involved in these differences have been marked by a vertical single line () in the outer margin. Appendix B gives a list of the corresponding technical differences and their reasons. This part also makes the following editorial changes:
-- Added "Part 7: Digital Proofing" and "Part 8: Digital Printing" of this standard in the foreword; - Modified the order of normative references in accordance with the requirements of GB/T1.1; - Modified "Appendix B in ISO12647-1:2004" in 4.2.2 of this part to "Appendix C in GB/T17934.1-1999"
Changed the unit of screen line number from "cm-1" to "line/cm" - Moved the notes of Table 1 to Table 1 in accordance with the requirements of GB/T1.1; - Added Note 3 to Table 1;
- Added the information about circular in 4.2.5 of this part. Notes on the shape of dots; - Added informative Appendix A, providing the structural changes of this part compared with ISO12647-6:2006; - Added informative Appendix B, providing the technical differences between this part and ISO12647-6:2006 and their reasons; - Added informative Appendix C, providing the control range of the solid reflection density value of the printing primary color; - Added informative Appendix D, providing a comparison table of centimeter and inch screen counts; - Modified Appendix A in ISO12647-6:2006 to Appendix E in this part; - Added 3 references of reference value to my country's flexographic printing industry; According to the requirements of GB/T1.1, the order of references was modified. This part was proposed by the General Administration of Press and Publication.
This part is under the jurisdiction of the National Technical Committee for Printing Standardization (SAC/TC170). Drafting organizations of this part: Shanghai Printing Technology Research Institute, Wuhan Huayi Flexo Environmental Technology Co., Ltd., Flint Group Flexo Products Division, Shenzhen Yingjie Laser Digital Platemaking Co., Ltd., Shanghai Zhengwei Printing Co., Ltd., Shanghai Fancai Image Equipment Co., Ltd., Shanghai Zim
GB/T17934.6—2014
Quan Label Co., Ltd., Bobst (Shanghai) Co., Ltd., Esko Trading (Shanghai) Co., Ltd., Flexographic Printing Branch of China Printing Technology Association.
Drafting persons of this part: Xue Xianhua, Wu Hongyi, Zheng Qihong, Liu Tie, Li Xiangchun, Mo Chunjin, Wang Yang, Ge Yan, Bao Wei, Gong Ren, V
GB/T17934.6—2C14
GB/T17934 provides parameters, target values and error ranges for process control for the most important printing methods in the printing industry, and GB/T17934.1 is the basis of this standard. It mainly provides the following information: 1. To determine the visual characteristics of halftone proofs and printed products, provide the minimum settings of basic parameters for printing process control; define basic terms in printing process control; measurement methods and report formats.
This part of GB/T17934 lists the basic parameter values or settings specified in GB/T17934.1 and the relevant technical properties of halftone flexographic products, and also specifies some useful other parameters. The purpose of proofing is to provide a simulation effect as close as possible to the visual characteristics of the final printed product. In order to visually match the effect of the printed product, non-press proofing samples will have certain differences in solid density, hue and gradation increase from the values on the actual printing press. Factors causing such differences include gloss, light scattering (printing materials or colorants), metamerism and transparency. The degree of difference is more obvious for non-press proofing samples that are very different from the printing materials, colorants and technologies used in flexographic printing processes. In this case, the user or supplier should ensure that appropriate corrections are made. V
1 Scope
Printing technology--Process control of halftone separations
Proofing and finished printing products--Part 6: Flexographic printing
GB/T17934.6—2014
This part of GB/T17934 is intended to specify the process parameters and parameter values to be applied when using flexographic four-color printing process in packaging and publishing printing. These parameters and parameter values are selected taking into account the entire printing process, covering the various steps such as color separation, color separation output, plate making, proofing, printing and surface finishing. This part is applicable to printing on white substrates or plastic films with white coating on the surface.
This part can be applied to:
--Products such as labels, cartons, corrugated boxes and flexible packaging printed by flexographic printing; Publications such as books, product samples and commercial printed materials printed by flexographic printing.
- Halftone and continuous tone proofing process for simulating the color effect of flexographic printing products. 2 Normative references
The following documents are indispensable for the application of this document. For all references with dates, only the versions with dates apply to this document. For all references without dates, the latest versions (including all amendments) apply to this document. GB/T11501 Photographic density measurement Part 3: Spectral conditions (ISO5-3: 1995, IDT) GB/T17934.1-1999 Printing technology - Process control of halftone color separations, samples and printed products - Part 1: Parameters and test methods (ISO12647-1:1996, eqv) GB/T19437 Printing technology - Spectral measurement and colorimetric calculation of printed images (ISO13655:1996, IDT) GB/T20439 Printing technology - Prepress data exchange - Input data for four-color printing feature description (ISO12642:1996, IDT)
Printing technology - Color and transparency of printing ink sets for four-colour printing Part 5.Flexographic printing (Graphic technologyISO2846-5E
gyColour and transparency of printing ink sets for four-colour printingPart 5.Flexographic printing) 3 Terms and definitions
The terms and definitions defined in GB/T17934.1-1999 apply to this document. 4 Technical requirements
4.1 Overview
Generally, the digital files or color separations provided for printing should be accompanied by proofs, unless the parties concerned have reached a corresponding agreement in the form of a contract. The proofs delivered should be able to simulate the effect of the printed product under subsequent production conditions and comply with the contents described in 4.3. For this purpose, verification should be carried out by measuring the control strips printed on the proofs together with the graphics or using similar control means during subsequent printing. Note: 4.2 and 4.3 are arranged in the order specified in GB/T17934.11999, namely basic principles, definition of data, measurement conditions and reporting methods.
GB/T17934.6—2014
Data files, color separations and printing plates
4.2.1 Data files
The data delivered for printing should be in CMYK color format or three-component (usually RGB) color format, and the printing conditions to be used should be indicated. The printing conditions are contained in the characterization data registry maintained by the International Color Consortium (ICC). For files in CMYK format, the names in the ICC characterization data registry can be used as the identification of the printing conditions without embedding an ICC output color profile. If the printing conditions to be used are not contained in the above characterization data registry, an ICC output color profile should be embedded. If the data is not in CMYK format, the data should be embedded in an ICC input color profile or defined in other colorimetric ways, and a CMYK ICC output color profile should be included, indicating the color space conversion method used when used with the output profile. 4.2.2 Separation or Plate Quality
The resolution of the laser imagesetter or direct platesetter should be set based on the ability to reproduce more than 100 gradation steps. Unless otherwise specified, the transmission density of the large non-transparent area of the matte color separation negative film should not be less than 3.50; the transmission density value of the transparent part should not be greater than 0.06. The measurement shall be made using a (UV) transmission densitometer, whose spectral characteristics conform to the ISO1 density values specified in GB/T11501.
The dot edge width (virtual edge or jagged edge) shall not be greater than 1/40 of the screen width, and the halftone dots shall not show obvious fragmentation. In addition to the requirements for the density value of the transparent part of the film, the quality of the color separation film can be evaluated according to Appendix C in GB/T17934.1-1999.
4.2.3 Screening lines (color separation film or printing plate) The screening lines shall be within the relevant range listed in Table 1. Table 1 Screening Line Range
Substrate Type
Corrugated Board
Uncoated Paper
Coated Paper
Unit: Lines per Centimeter
Film/Foil
Note 1: If the screening line is outside the range specified in Table 1, the basic principles specified in GB/T17934.1-1999 are still valid, but the values of this part of the specification may be different.
Note 2: When computer screening, in order to minimize moire fringes, there will usually be a small change in the "screening line number" and "screening angle" between different printing color separations.
Note 3: See Appendix D for the conversion table of inch and centimeter screen lines. 4.2.4 Screening angle (color separation film or printing plate) For screen lines without a main axis, the normal difference in the screen angle of cyan, magenta and black plates should be 30°, and the angle difference between the yellow plate and other color plates should be 15°; the screen angles of each color plate and the screen pattern engraved by the anilox roller shall not be the same, and the angle difference between the two should be 7.5. Figure 1 is a schematic diagram of the setting of the screen angle.
Reference direction (0)
Figure 1 Schematic diagram of the setting of the screen angle
4.2.5 Dot shape and its relationship with the tone value (color separation film or printing plate) Circular dots are preferably used.
Note: Circular dots have a smaller tone increase than dots of other shapes. 4.2.6 Image size error (color separation film or printing plate) GB/T17934.6—2014
Under stable conditions, the change in the diagonal length of a set of color separation films or printing plates should not be greater than C.C1%. Note: This error includes the repeatability error of the laser imagesetter or direct plate-making machine and the error selected by our film department. 4.2.7 The total of tone values (data file or color separation film) should be controlled within the following range:
Corrugated board: 270%~300%;
Coated paper: 280%~300%;
Uncoated paper: 290%~320%;
Film/foil: 270%~290%.
Note: The total of tone values given above is for general reference only. The total of tone values is actually subject to the type of ink used (solvent-based, water-based, UV-based, etc.), substrate, dry media method and inline processing technology. Testing on the printing press can provide the appropriate total of tone values for a specific process. 3 Gray balance (data file or color separation film)
One gray balance condition alone is usually not enough to ensure that the various substrates, various combinations of black and various printing inks used under given process conditions produce non-color effects. The correct gray balance can be determined from the relevant color management characteristic file, which usually depends on the components that make up black.
See Appendix E for approximate values for controlling gray balance. 4.3 Proofing samples or printed products
4.3.1 Overview
According to the format basically set by GB/T20439, provide colorimetrically based characterization data for the values specified in 4.3.2.1, 4.3.2.3 and 4.3.5.1.
GB/T17934.6—2014
Visual characteristics of the image part
Substrate color
Substrates included in Table 1:
Corrugated board (coated and uncoated); coated paper;
Uncoated paper;
Film;
The white color should conform to the chromaticity value range shown in Table 2. The substrate used for proofing should be exactly the same as the substrate used for printing. If it is not exactly the same, the proofing can use a substrate that is close to the printing in terms of color, gloss, type of printing surface material (such as paper, plastic, cardboard) and grammage.
Note: If the final printed product needs to be surface-finished, it will seriously affect the color of the substrate. See the note in 4.3.2.2. Table 2 Color range of substrates
4.3.2.2 Gloss of substrates
Unit is 1
The gloss of the proofing substrate should be basically consistent with the gloss of the substrate used in the actual printing. If consistency cannot be achieved, the closest material should be selected from the types of substrates listed in 4.3.2.1 for printing press proofing. Note: If the final printed product is required to be surface finished, the gloss will be seriously affected. In strict cases, the effect of color separation can only be judged by providing a sample with a surface gloss that is very close to the surface gloss of the finished printed product. In the case of off-line finishing, in order to help the image of the printed product match the effect of the proof sample image in the preparation stage, it is a good idea to provide the printing press operator with two proof samples: one sample with a surface gloss consistent with the unfinished printed product, and the other sample with a surface gloss consistent with the final surface finished print. 4.3.2.3 Ink Color
When using the printing primary color inks defined in ISO2846-5, the values of L:, Q, and b' in the CIELAB chromaticity coordinates of the primary color solid on the proofing sheet shall comply with the values specified in Table 3. The CIELAB chromaticity coordinates of the two-color overprinting ink layer other than black should comply with the values specified in Table 3. During the printing process, the deviation between the primary color solid blocks of the printed sample and the proofing sheet should not exceed the deviation range specified in Table 4. If a matching proofing sheet cannot be provided, the color values in Table 3 should be used as the target values. In printing production, the tolerance of the printing primary color solid blocks is subject to the following conditions, namely: at least 68% of the color difference between the printed product and the printed sample should not exceed half of the tolerance value specified in Table 4. Table 3
Corrugated board·/uncoated paper
CIELAB values of printed primary colors
Substrate type
Coated paper
Film/foil
Unit: 1
Corrugated board·/uncoated paper
Coated or uncoated;
Table 3 (continued)
Substrate type
Coated paper
bMeasured according to the provisions of GB/T19437, using a white, matte, opaque substrate with L·>92, C<3;. According to the printing color sequence of yellow-cyan-poinsettia. GB/T17934.6—2014
Unit: 1
Film/foil
Note 1: The distribution of the color difference △E. values is not Gaussian, but skewed. However, for the sake of consistency, 68% was chosen as the limit. This is analogous to the Gaussian distribution, where 68% is within the range of plus or minus one standard deviation from the mean. NOTE 2: If the final printed product is to be surface-finished, the final color balance is expected to be significantly different from that before finishing, see the notes to 4.3.2.1 and 4.3.2.2. NOTE 3: The values of the secondary colors red, green and blue depend on certain conditions, including the printing color sequence, the rheology and transparency of the ink, the mechanical properties of the printing press and the surface characteristics of the substrate. Therefore, when the CMY values of the primary colors meet the values specified in Table 3, it is not sufficient to ensure that the secondary colors meet the values specified in Table 3.
NOTE 4: In the printing process, when the instrument, ink and substrate remain unchanged, the density value is very valuable for process control, see GB/T13722, however, in general, the definition of the color balance by density value cannot achieve the required accuracy. Therefore, in this part, only the reflection density value is recommended to be used for the determination of tone value. According to the provisions of GB/T18722, the printer should first use the printing press to print the correct solid color, and then use the instrument to measure the density value from the printed sample, so that these density values can be well used as the target value of process control in the printing process. Appendix C provides the control range of the reflection density value of the solid color of the printing original color for reference. Table 4 CIELAB color difference AEab color difference of the solid color of the printing original color
Ink gloss
Unit is 1
No regulation.
Note: If it is confirmed that it is necessary to specify the gloss of the solid ink layer, it is advisable to measure and record the surface gloss of the solid area of the oil on the printed sheet after fixation at an approved angle of incidence.
4.3.3 Tone value reproduction range
The dot shape within the tone value range given in Table 5 (on the color separation film or prepress data file) should be stably and consistently transferred to the printed product, and the tone value of the important part of the image should not exceed the specified range. 5
GB/T17934.6-—2014
Tonal value range
Image position error
Table 5 Tonal value range (color separation sheet or data file) Substrate type
Corrugated board
5%~80%
Uncoated paper
5%~80%
Coated paper
3%~85%
Film/foil
2%~90%
The maximum position deviation between the centers of any two-color printed images on corrugated board substrates shall not exceed C.04% of the diagonal length of the printing plate. The maximum position deviation for other types of substrates shall not exceed 0.02% of the diagonal length of the printing plate. 4.3.5 Tone increase value
Target value
The tone increase value of flexographic printing is closely related to the specific combination of the ink, printing substrate and printing press used. Table 6 gives the reference value of tone increase. In the case that the printing conditions related to the tone increase are not provided, the values in Table 6 should be used for color separation and proofing. If different tone increase values are required for actual printing, necessary corrections should be made at the platemaking stage. The method of tone increase should comply with the provisions of GB/T17934.1-1999. Note: Due to differences in substrates, it may be necessary to make fine adjustments on the printing press to generate a corresponding tone curve for each substrate. Table 6 Tone percentage increase for various substrates Difference Block tone value
Corrugated board
Uncoated paper
Substrate type
Coated paper
Film/foil
Note: Density values are measured in accordance with GB/T17934.1-1999, in accordance with ISO state E response and polarization settings specified in GB/T11501. For ISO state T response without polarization settings, the midtone values of cyan, magenta and black are roughly equivalent to the values shown in the table, and the value of yellow will be less than 2%. Tone error and midtone expansion
At the tone (dot) values of 25%, 50%, and 75%, the deviation of the tone value of the proof or printed sample from the specified value should not exceed 5%. The standard deviation of the tone value statistics shall not exceed 4%, and 68% of the printed products shall not exceed 4% of the printed samples; the midtone expansion (tolerance between C, M, and Y) of the proof or printed product shall not exceed 5%. 6
5 Test method: Tone value and tone increase value of printed products GB/T17934.6-2014
According to 5.3 of GB/T17934.1-1999 and the following additional requirements, single or grouped control blocks should be distributed on the printing format and printed with the printed product, and the screen count should be within the range of 18 lines/cm to 60 lines/cm. The dot shape, screen count and screen angle of the directly generated control block should be the same as the parameters of the printed body. Its tone value range should be at least within the range specified in Table 5 and the same as the tone value range used for the printed body. The minimum dot size of non-periodic screening should be 50μm. The control block should meet the requirements of this part of GB/T17934. If a film control strip is used, the density value of the opaque part shall be at least 4.0 higher than the density value of the transparent part, and the dot edge width shall not exceed 2μm. Note: See the note to Table 6.
Reporting of printing conditions
In the color management related to color management, such as the color management characterization table or the color management characteristic file based thereon, for the printing conditions defined in Tables 1 to 6 of this part of GB/T 17934, the following reporting format should be followed: "Printing in accordance with GB/T 17934.6, "Flexographic printing", "Substrate type", "Line screen count per centimeter"; the substrate types listed in Tables 1, 3, 5, and 6 are abbreviated as "PS1" to "PS4". Example 1: "Printing in accordance with CB/T 17934.6, flexographic printing, substrate type 3, and the line screen count is 52 lines/cm\. Example 2: FL_PS3_F52.Note 2, Note 3: The values of the secondary colors red, green and blue depend on certain conditions, including the printing color sequence, the rheology and transparency of the ink, the mechanical properties of the printing press and the surface characteristics of the substrate. Therefore, when the CMY values of the primary colors meet the values specified in Table 3, it is not enough to ensure that the secondary colors meet the values specified in Table 3.
Note 4: In the printing process, when the instrument, ink and substrate remain unchanged, the density value is very valuable for process control, see GB/T13722. However, in general, the definition of the color by density value cannot achieve the required accuracy. Therefore, in this part, only the reflection density value is recommended for the determination of the gradation value. According to the provisions of GB/T18722, the printer should first use the printing press to print the correct solid color, and then use the instrument to measure the density value from the printed sample, so that these density values can be well used as the target value of process control in the printing process. Appendix C provides the control range of the solid reflection density value of the primary color for reference. Table 4 CIELAB color difference AEab color difference of printed primary colors
Ink gloss
Unit is 1
No regulation.
Note: If it is confirmed that it is necessary to specify the gloss of the solid ink layer, it is advisable to measure and record the surface gloss of the solid area of the oil on the printed sheet after fixation at an approved angle of incidence.
4.3.3 Tone value reproduction range
The dot shapes within the tone value range given in Table 5 (on the color separation film or prepress data file) should be stably and consistently transferred to the printed product, and the tone value of the important part of the image should not exceed the specified range. 5
GB/T17934.6-—2014
Tonal value range
Image position error
Table 5 Tonal value range (color separation sheet or data file) Substrate type
Corrugated board
5%~80%
Uncoated paper
5%~80%
Coated paper
3%~85%
Film/foil
2%~90%
The maximum position deviation between the centers of any two-color printed images on corrugated board substrates shall not exceed C.04% of the diagonal length of the printing plate. The maximum position deviation for other types of substrates shall not exceed 0.02% of the diagonal length of the printing plate. 4.3.5 Tone increase value
Target value
The tone increase value of flexographic printing is closely related to the specific combination of the ink, printing substrate and printing press used. Table 6 gives the reference value of tone increase. In the case that the printing conditions related to the tone increase are not provided, the values in Table 6 should be used for color separation and proofing. If different tone increase values are required for actual printing, necessary corrections should be made at the platemaking stage. The method of tone increase should comply with the provisions of GB/T17934.1-1999. Note: Due to differences in substrates, it may be necessary to make fine adjustments on the printing press to generate a corresponding tone curve for each substrate. Table 6 Tone percentage increase for various substrates Difference Block tone value
Corrugated board
Uncoated paper
Substrate type
Coated paper
Film/foil
Note: Density values are measured in accordance with GB/T17934.1-1999, in accordance with ISO state E response and polarization settings specified in GB/T11501. For ISO state T response without polarization setting, the midtone values of cyan, magenta and black are roughly equivalent to the values shown in the table, and the value of yellow will be less than 2%. Tone error and midtone expansion
At the tone (dot) values of 25%, 50%, and 75%, the tone value of the proof or printed sample should not deviate from the specified value by more than 5%. The standard deviation of the tone value statistics shall not exceed 4%, and 68% of the printed products shall not exceed 4% of the printed samples; the midtone expansion (tolerance between C, M, and Y) of the proof or printed product shall not exceed 5%. 6
5 Test method: Tone value and tone increase value of printed products GB/T17934.6-2014
According to 5.3 of GB/T17934.1-1999 and the following additional requirements, single or grouped control blocks should be distributed on the printing format and printed with the printed product, and the screen count should be within the range of 18 lines/cm to 60 lines/cm. The dot shape, screen count and screen angle of the directly generated control block should be the same as the parameters of the printed body. Its tone value range should be at least within the range specified in Table 5 and the same as the tone value range used for the printed body. The minimum dot size of non-periodic screening should be 50μm. The control block should meet the requirements of this part of GB/T17934. If a film control strip is used, the density value of the opaque part shall be at least 4.0 higher than the density value of the transparent part, and the dot edge width shall not exceed 2μm. Note: See the note to Table 6.
Reporting of printing conditions
In the color management related to color management, such as the color management characterization table or the color management characteristic file based thereon, for the printing conditions defined in Tables 1 to 6 of this part of GB/T 17934, the following reporting format should be followed: "Printing in accordance with GB/T 17934.6, "Flexographic printing", "Substrate type", "Line screen count per centimeter"; the substrate types listed in Tables 1, 3, 5, and 6 are abbreviated as "PS1" to "PS4". Example 1: "Printing in accordance with CB/T 17934.6, flexographic printing, substrate type 3, and the line screen count is 52 lines/cm\. Example 2: FL_PS3_F52.Note 2, Note 3: The values of the secondary colors red, green and blue depend on certain conditions, including the printing color sequence, the rheology and transparency of the ink, the mechanical properties of the printing press and the surface characteristics of the substrate. Therefore, when the CMY values of the primary colors meet the values specified in Table 3, it is not enough to ensure that the secondary colors meet the values specified in Table 3.
Note 4: In the printing process, when the instrument, ink and substrate remain unchanged, the density value is very valuable for process control, see GB/T13722. However, in general, the definition of the color by density value cannot achieve the required accuracy. Therefore, in this part, only the reflection density value is recommended for the determination of the gradation value. According to the provisions of GB/T18722, the printer should first use the printing press to print the correct solid color, and then use the instrument to measure the density value from the printed sample, so that these density values can be well used as the target value of process control in the printing process. Appendix C provides the control range of the solid reflection density value of the primary color for reference. Table 4 CIELAB color difference AEab color difference of printed primary colors
Ink gloss
Unit is 1
No regulation.
Note: If it is confirmed that it is necessary to specify the gloss of the solid ink layer, it is advisable to measure and record the surface gloss of the solid area of the oil on the printed sheet after fixation at an approved angle of incidence.
4.3.3 Tone value reproduction range
The dot shapes within the tone value range given in Table 5 (on the color separation film or prepress data file) should be stably and consistently transferred to the printed product, and the tone value of the important part of the image should not exceed the specified range. 5
GB/T17934.6-—2014
Tonal value range
Image position error
Table 5 Tonal value range (color separation sheet or data file) Substrate type
Corrugated board
5%~80%
Uncoated paper
5%~80%
Coated paper
3%~85%
Film/foil
2%~90%
The maximum position deviation between the centers of any two-color printed images on corrugated board substrates shall not exceed C.04% of the diagonal length of the printing plate. The maximum position deviation for other types of substrates shall not exceed 0.02% of the diagonal length of the printing plate. 4.3.5 Tone increase value
Target value
The tone increase value of flexographic printing is closely related to the specific combination of the ink, printing substrate and printing press used. Table 6 gives the reference value of tone increase. In the case that the printing conditions related to the tone increase are not provided, the values in Table 6 should be used for color separation and proofing. If different tone increase values are required for actual printing, necessary corrections should be made at the platemaking stage. The method of tone increase should comply with the provisions of GB/T17934.1-1999. Note: Due to differences in substrates, it may be necessary to make fine adjustments on the printing press to generate a corresponding tone curve for each substrate. Table 6 Tone percentage increase for various substrates Difference Block tone value
Corrugated board
Uncoated paper
Substrate type
Coated paper
Film/foil
Note: Density values are measured in accordance with GB/T17934.1-1999, in accordance with ISO state E response and polarization settings specified in GB/T11501. For ISO state T response without polarization settings, the midtone values of cyan, magenta and black are roughly equivalent to the values shown in the table, and the value of yellow will be less than 2%. Tone error and midtone expansion
At the tone (dot) values of 25%, 50%, and 75%, the deviation of the tone value of the proof or printed sample from the specified value should not exceed 5%. The standard deviation of the tone value statistics shall not exceed 4%, and 68% of the printed products shall not exceed 4% of the printed samples; the midtone expansion (tolerance between C, M, and Y) of the proof or printed product shall not exceed 5%. 6
5 Test method: Tone value and tone increase value of printed products GB/T17934.6-2014
According to 5.3 of GB/T17934.1-1999 and the following additional requirements, single or grouped control blocks should be distributed on the printing format and printed with the printed product, and the screen count should be within the range of 18 lines/cm to 60 lines/cm. The dot shape, screen count and screen angle of the directly generated control block should be the same as the parameters of the printed body. Its tone value range should be at least within the range specified in Table 5 and the same as the tone value range used for the printed body. The minimum dot size of non-periodic screening should be 50μm. The control block should meet the requirements of this part of GB/T17934. If a film control strip is used, the density value of the opaque part shall be at least 4.0 higher than the density value of the transparent part, and the dot edge width shall not exceed 2μm. Note: See the note to Table 6.
Reporting of printing conditions
In the color management related to color management, such as the color management characterization table or the color management characteristic file based thereon, for the printing conditions defined in Tables 1 to 6 of this part of GB/T 17934, the following reporting format should be followed: "Printing in accordance with GB/T 17934.6, "Flexographic printing", "Substrate type", "Line screen count per centimeter"; the substrate types listed in Tables 1, 3, 5, and 6 are abbreviated as "PS1" to "PS4". Example 1: "Printing in accordance with CB/T 17934.6, flexographic printing, substrate type 3, and the line screen count is 52 lines/cm\. Example 2: FL_PS3_F52.Density values were measured from 1 to 1999, in accordance with the ISO state E response and polarization settings specified in GB/T11501. For the ISO state T response without polarization settings, the midtone values for cyan, magenta and black are roughly equivalent to those shown in the table, and the value for yellow is less than 2%. Tone error and midtone spread
At 25%, 50%, and 75% of the tone (dot) value, the deviation of the tone value of the proof or printed sample from the specified value should not exceed 5%. The standard deviation of the tone value statistics should not exceed 4%, and 68% of the prints should not exceed 4% of the printed sample; the midtone spread (tolerance between C, M, and Y) of the proof or printed product should not exceed 5%. 6
5 Test method: Tone value and tone addition value of printed products GB/T17934.6—2014
According to 5.3 of GB/T17934.1-1999 and the following additional requirements, single or grouped control blocks should be distributed on the printing format and printed together with the printed product, and the screen count should be in the range of 18 lines/cm to 60 lines/cm. The dot shape, screen count and screen angle of the directly generated control blocks should be the same as the parameters of the printed body. The range of tone values should be at least within the range specified in Table 5 and the same as the range of tone values used for the printed body. The minimum dot size for non-periodic screening should be 50μm. The control blocks should meet the requirements of this part of GB/T17934. If a film control strip is used, the density value of the opaque part should be at least 4.0 higher than the density value of the transparent part, and the dot edge width should not exceed 2μm. Note: See the note to Table 6.
Reporting of printing conditions
In areas related to color management, such as color management characterization tables or color management characteristic files based thereon, for the printing conditions defined in Tables 1 to 6 of this part of GB/T17934, the following reporting format should be followed: "Printing in accordance with GB/T17934.6, "Flexographic printing", "Substrate type", "Line screen count per centimeter"; the substrate types listed in Tables 1, 3, 5, and 6 are abbreviated as "PS1" to "PS4". Example 1: "Printing in accordance with CB/T17934.6, flexographic printing, substrate type 3, line screen count of 52 lines/cm." Example 2: FL_PS3_F52.Density values were measured from 1 to 1999, in accordance with the ISO state E response and polarization settings specified in GB/T11501. For the ISO state T response without polarization settings, the midtone values for cyan, magenta and black are roughly equivalent to those shown in the table, and the value for yellow is less than 2%. Tone error and midtone spread
At 25%, 50%, and 75% of the tone (dot) value, the deviation of the tone value of the proof or printed sample from the specified value should not exceed 5%. The standard deviation of the tone value statistics should not exceed 4%, and 68% of the prints should not exceed 4% of the printed sample; the midtone spread (tolerance between C, M, and Y) of the proof or printed product should not exceed 5%. 6
5 Test method: Tone value and tone addition value of printed products GB/T17934.6—2014
According to 5.3 of GB/T17934.1-1999 and the following additional requirements, single or grouped control blocks should be distributed on the printing format and printed together with the printed product, and the screen count should be in the range of 18 lines/cm to 60 lines/cm. The dot shape, screen count and screen angle of the directly generated control blocks should be the same as the parameters of the printed body. The range of tone values should be at least within the range specified in Table 5 and the same as the range of tone values used for the printed body. The minimum dot size for non-periodic screening should be 50μm. The control blocks should meet the requirements of this part of GB/T17934. If a film control strip is used, the density value of the opaque part should be at least 4.0 higher than the density value of the transparent part, and the dot edge width should not exceed 2μm. Note: See the note to Table 6.
Reporting of printing conditions
In areas related to color management, such as color management characterization tables or color management characteristic files based thereon, for the printing conditions defined in Tables 1 to 6 of this part of GB/T17934, the following reporting format should be followed: "Printing in accordance with GB/T17934.6, "Flexographic printing", "Substrate type", "Line screen count per centimeter"; the substrate types listed in Tables 1, 3, 5, and 6 are abbreviated as "PS1" to "PS4". Example 1: "Printing in accordance with CB/T17934.6, flexographic printing, substrate type 3, line screen count of 52 lines/cm." Example 2: FL_PS3_F52.
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