The hottest interpretation of offset new color cod

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Interpretation of the new color code for offset printing

the new color code ISO 2846-1:2000 of the international organization for standardization has been launched, and many customers and printing plants have begun to use this new color code

1 color standard and process standard

the goal of each printing is to reproduce the original as faithfully as possible and keep the color change small throughout the printing. In order to approach this goal, in 1989, the German printing and Media Association and Fogra Institute published the manual of offset process standardization, which has been incorporated into ISO 12647-2:1998 process standards. The book is currently being revised and is expected to be published in 2004

in order to obtain the consistency of printing effect, in addition to complying with process parameters, the consistency or similarity between paper and ink is also very important. Therefore, in the process standard, the printing paper is divided into five types, and different color values are also specified for the primary color ink according to the paper type. However, ISO 2846-1 specifies the color characteristics of color coded inks

the purpose of formulating this standard and its predecessor DIN 16539 (European color standard) is to enable offset printers to obtain a complete set of color standard inks from different sources. Using this kind of ink can produce similar colors as long as it is printed on the same substrate with a general ink layer thickness. When the color standard ink consistent with the standard is used to print on the matte APCO II/II test paper with the help of a proofer within the specified ink layer thickness range and under standard conditions (ISO 2834), the color value specified in ISO 2846-1 can be achieved within the specified allowable deviation. Under standardized conditions and within the specified tolerance, the color value specified in the above process standard can be obtained with officially printed paper

the figure shows the offset color gamut on type I (-- line range) and type IV paper (... Line range) according to ISO 12647-2. According to ISO 2846-1, the color on APCO II/II paper is encouraging, although the reports so far are spatial

the inks involved in part 1 of ISO 2846 family standards are offset printing inks for sheet fed offset printing, thermosetting web offset printing and UV curing. Another applicable scope of the standard is continuous printing (no intermittent images or continuous tables). Other parts of the standard involve newspaper printing (Part 2), gravure printing (Part 3), silk printing (Part 4) and flexographic printing (Part 5, which is still under development)

2 the European color standard has lost its significance

color standard DIN 16 this experiment adopts C language programming 539, which is of great significance all over the world as a "European standard", and was published as an international standard ISO 2846 in 1975. The standard was formulated on the basis of extensive research by experts from some European countries in the 1960s. At the end of the 1980s, the ratio of color standard ink on the market to DIN 16539 has changed. Therefore, the standard was revised according to the data. The units that provide data are:

· the German printing Research Institute (Fogra) collected the color standard inks commonly used by German ink manufacturers in the market:

· European cepe Association:

· the National Federation of printing ink manufacturers (NAPIM) provides swop, and the ink (web adhesive printing plate specification) is the basis of color standard ink data:

· Japan Ink Manufacturers Federation, Determine a set of standard inks based on the color code inks sold in the market, and its name is.Japan color SF 90

the experts of iso/tc 130 Printing Technical Committee concluded that the only set of color values within the appropriate tolerance may represent the suggestion of revising the standard. Compared with the primary color standard, there are other modifications and supplements. Such as black, new transparency, and the abolition of the provisions of the intermediate color, covering UV curing ink

the European offset color code (DIN 16539), or European color code for short, has now lost its meaning and has been withdrawn. But the concept of European color code is still in many people's minds. The new color code ISO 2864-l:2000 has been gradually promoted

3iso color codes can be seen everywhere.

according to the ink Association, 80% of the color code inks are now consistent with the new color standards within the tolerance range. However, in order to achieve special effects or meet special requirements, some color deviations are allowed. For example, the hue of furniture samples should be warmer, on the contrary, the hue of computer and car samples should be cooler. It is impossible to try to affect the characteristics of the printed image by changing the ink color during printing. 3 Furnace size: Φ one hundred and ten × 350mm through. The color should be changed before printing, and the color can be better controlled with the help of color management software

4 tolerance

although ISO standards unify color standard inks under one standard, there are still aesthetic and hobby differences in different regions. People in Asia and America like cool colors, while Europeans like warm colors. Only this difference fluctuates within the standard tolerance. Due to the close relationship between enterprises and the exchange of relevant data and color management documents, there are not too many obstacles in the publicity and implementation of international standards. In the long run, there will be another unified standard. Now all inks that aim at the rated value of ISO 2846-1 can be provided according to the needs of customers in any case

5 feasibility of primary color

the primary color specified in the standard should have good feasibility, that is to say, the pigment with light resistance and chemical resistance should have good processability. For example, the din color code for cool colors (DIN 16509) can achieve a large color gamut, but its color light resistance is poor. Although yellow and magenta are often expected to be slightly red, this obviously limits the color gamut that can be reached in the green range

6 color gamut of standard color standard

first of all, the color value mentioned in ISO 2846-1 color standard does not involve actual printed matter. As shown in the previous figure, although there is only a small deviation between the spatial positions of the primary colors on the inspection paper APCO Ⅱ/Ⅱ and the application paper I, there is a significant difference in the non coated paper (type IV paper). In practice, we tried to readjust the color value of the color standard according to the application paper, but failed. Because this color value is only applicable to laboratory printing on test paper. In addition, this is also applicable to the ink color specified in DIN 16539 (European color code 1). In actual printing, if the ink specified in accordance with ISO 2846-l is used to print on the paper of the model specified in ISO 12647-2, the color value specified in the process standard (ISO 12647-2) should be achieved (within the specified tolerance)

7 limits of color standards

color standards only specify the color characteristics of field color code inks. However, in actual printing, the field is rarely used, and most of it is eye tone. Its color is not only determined by the ink color characteristics on the field, but also greatly affected by dot expansion. Therefore, we hope to specify the dot enlargement caused by ink in the color standard. Although the influence of ink and its printability on dot enlargement is not negligible, its degree of influence is not determined by printing ink alone. This must be combined with the paper materials and machine conditions used to determine which have a significant impact on the point expansion. Even if we try to provide the ink with the performance of ensuring "ideal point enlargement", and this point enlargement is measured in the company's own printing plant or the same paper on the customer's side, the point enlargement degree will still change when another printing plant uses the same paper to print under unique printing conditions. In addition, the storage of ink is often related to the change of rheological property (hysteresis), which will lead to the change of dot enlargement rate even under the same printing conditions

therefore, printing plants should pay attention to that inks with different storage times cannot be mixed with each other. Due to technical reasons, it can not meet the requirements of the China Rubber Industry Association for the expansion of ink caused by the publicly released tire classification standards, tire label management regulations and tire label patterns of the China Rubber Industry Association at the activities of the second green tire safety week. Each ink manufacturer should determine the production of its products according to the available raw materials, prices and its own manufacturing conditions. Therefore, the ink factory tries to make products that can meet the needs of customers as much as possible. Color, fluidity, dryness and post press processing are all important aspects. However, this does not mean that all ink manufacturers use the same formula or the same conditions to manufacture a color coded ink. This manufacturing difference will affect the ink viscosity and the related printing dot expansion. You can't leave the ink performance alone. You can control the point expansion by selecting other materials (blanket, fountain solution, paper) and adjusting machine parameters (pressure, fountain solution supply)

the amount of ink received during wet press wet printing has a great impact on the quality of the printed image. To a large extent, the ink performance determines the amount of ink received during wet press wet printing, especially the viscosity affected by offset wetting. In addition, the permeability of ink and paper, as well as the printing speed or the interval time before the next ink is printed, are the factors that affect the amount of wet press wet ink. Permeability plays an important role in this problem, because during the penetration process, the liquid components of the ink are separated by the capillary action of the paper coating, which increases the viscosity (viscosity) of the ink layer printed first, thus changing the inkability of the ink printed later

it should also be noted here that these effects from different aspects on the inkability of offset printing inks cannot be listed in detail or specified in the ink standard. Therefore, we must follow the common methods of standard printing: printing test version I - measuring test version - Prepress Cooperation (color management)

the purpose of the color tolerance specified in ISO 12647-2 process standard for batch printing is to meet the standard even under the common fluctuations of ink supply and dot expansion. Inevitable mutual matching effects in machine adjustment, such as printing speed or water and ink transportation, and the resulting changes in water and ink balance and machine temperature, will inevitably lead to point expansion and fluctuations in ink density and color space position measurements. The stricter requirements for tolerance than those specified in ISO 12647-2 process standard do not conform to the actual technology of offset printing

8 ink manufacturing

it is certain that first of all, printing plants cannot be directly linked with ISO 2846-1 color standard. This standard is more applicable to ink manufacturers, who can achieve the colors detailed in ISO 12647-2 by adopting this standard. After all, the field ink colors involved in the new version of ISO 12647-2 process standard, the offset process standard of the German printing and Media Association and the ICC document of ECI (European color Committee) are all based on the printing ink colors according to ISO 12647-1. Therefore, the printing factory can use the set of inks provided for true color printing. Because these inks are related to ISO color code and influential IC documents. However, no effective auxiliary method has been found for making laboratory proofing according to ISO 2846-1 color standard. (translated by xushiyuan)

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