Discussion on the most pre printing under the colo

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Prepress discussion: color management in the field of proofing (Part 2)

selecting a standard

adding color management to the workflow helps to improve the interoperability of colors (for example, the ability to share color information between devices). Therefore, if we can adopt a unified standard, it will make things very simple. However, in view of the current global economic situation and the repeated use of the same content in different places and on different media, we have never found a unified standard. Therefore, the biggest problem we are facing now is how to integrate multiple different standards

generally speaking, there are three types of standards: the first is customized or internal standards, which are mainly formulated by printing plants to improve the efficiency of their prepress and printing processes; The second is the unofficial standard, which has been recognized by most people and has been used in production for a long time (such as Photoshop sheetfed offset and adobe 98 RGB); The third is the recognized standard, which is officially issued and recognized by trade associations and other organizations (such as idealliance and ECI)

we may not be able to describe in detail the formulation process and status of all standards in this article, but a quick browse of all standards related to proofing is very helpful

European color Alliance (ECI) is an expert group, which is mainly committed to promoting the processing of media independent color data in the digital publishing system. The reference color space gravure standard issued by the organization has been successfully applied in the publishing gravure field in Europe since the spring of 2002

snap (specifications for newspaper advertising production) creates a color standard for newspaper printing

fogra (Graphic Technology Research Association) has created a color standard that can be widely used in Europe and set a set of target values for the proofing and certification system, although it is only a set of European standards

the international standards organization (ISO) has established a printing technical committee, which specializes in color printing, standard setting and measurement

ICC is mainly committed to promoting an open, neutral and cross platform color management system in the industry

idealliance (American International Digital Enterprise Alliance) is an industry organization headquartered in the United States. It has always been committed to developing and studying the best practices and standards in the printing industry. At present, it is responsible for managing the following standards: rotary offset printing parameter description (swop, mainly applied to long version rotary offset printing) and basic requirements for commercial offset lithography printing (gracol, mainly applied to short version commercial sheet fed printing), etc

harmonized standards

in view of such a wide range of industry standards, the success of a proofing workflow mainly depends on the determination of unified standards and the matching degree of each procedure in the workflow with this standard

in the global printing market, different printing houses may adopt different standards and working methods. In the same way, people can create printed content according to different standards. An article written three years ago may have been printed according to a standard; A magazine may be designed according to another standard; An advertising agency may make its own advertisements according to the third standard; A printing house may use the fourth standard for printing

whether it is a recognized standard, an unofficial standard or an internal standard, you should be able to handle it. So how do you manage them

the best way to solve this problem is to transfer the files to your own color space and make proofing according to the target space. For example, if the standard you get conforms to the swop standard, but you find that the color printed by the magenta unit of the printer is insufficient through proofing, you can make up for this difference by adjusting the printing documents of this unit. Your original proofing (before color conversion) can reflect the deficiency of red. The converted file shows the final effect after correction

make the standard work: connect the equipment with the characterization description file

the only reliable way to output the same file on two different proofing systems is to calibrate and test the characteristics of the two systems respectively. Imagine each manufacturer's printer driver for different models, and determine how it came to the printing plant after leaving the factory. During the installation of the system, each printer should be recalibrated according to recognized standards. Therefore, even if a clear color standard or proofing target is not found, the system can cooperate well

the operator should print the test samples regularly and measure them with a spectrophotometer, so as to find the problems in the system and correct them in time. This should be done no matter what. All equipment should be adjusted to the same standard state, so that their performance can be consistent, and the accuracy and repeatability of the production process can be guaranteed

however, this method also cuts off the connection between the calibration of digital printers and the characterization of printers. For each given ink/paper/printing condition, the printer must create a characterization description file or go through a characterization test process. As long as the characteristic files of a printer are changed, it means that the characteristic files of all printers/printers in the same network will be modified, and the final printing effect will be adversely affected. Therefore, it is generally believed that this is a high-risk/high investment/low return correction method

creating an independent printer characterization file and using the same printer characterization description file for all printers can ensure that the printer is always consistent with the color space when the characterization file is created. Therefore, any inkjet printer belonging to the same printer family can match with other printers anytime and anywhere as long as the same paper, ink and setting parameters are used. Please remember that the accuracy and repeatability of the whole proofing system are directly related to the quality of consumables and the consistency of operation. Therefore, the key is to calibrate the equipment frequently and use the best substrate, ink and technical service personnel as much as possible

when using the decentralized device characterization solution with strong endogenous R & D capability, the remote terminal can only receive the printer characterization description file and ensure that the output device is always within a specific tolerance range

this correction method can make the proofing system show the same color effect in different places. If you want to obtain the same (very close tolerance) proofing effect in a long time, or make the printing systems in different places achieve accurate color restoration, it is most important to master this correction method

if the printing plant can clearly distinguish the calibration, characterization test and program of the proofing system while adopting the industry standards, it is completely unnecessary for them to introduce color management experts. If you need to use a customized printer characterization description file, you need to let the color management expert generate an optimized color characterization description file. In the case of Remote Proofing, this characterization file can be sent to all remote locations, which greatly simplifies the process of achieving and maintaining color consistency

look, horse! No hands

in view of the above requirements and problems in the actual use of the proofing system, especially the remote proofing system, many potential Remote Proofing users do not have the courage to try

they are afraid to operate complex measuring instruments, unwilling to face the pressure of calibrating output equipment and creating complex characterization documents. All these have hindered the promotion of Remote Proofing System in the printing industry. Fortunately, technological advances have gradually removed these obstacles

the newly launched Designjet z2100 digital printer of HP redefines remote proofing. With the support of the built-in spectrophotometer, it can automatically perform the remote calibration procedure. In addition, as long as sufficient network bandwidth can be provided, the printer can be used as an independent device in a remote location without connecting to a local computer and an external spectrophotometer. Moreover, because its built-in spectrophotometer can detect each sample, this digital printer can also save users a lot of equipment and labor costs. To sum up, Designjet z2100 digital printer is a proofing solution worth considering

the advantages of this system are: it is a complete solution; Each sample produced is a high-quality contract proofing; It can repeat proofing on any HP Designjet z2100 printer anytime and anywhere; When users do not have color management knowledge, they can easily produce samples that meet industry standards; Fewer wrong samples can be produced, which can reduce the labor and material costs of proofing and improve customer satisfaction

in the past, to calibrate a printer at a remote location, users had to purchase a proofing program, or print test samples with the host system, and send them back to the host company's office for measurement. If you want to improve the repeatability of the proofing system, you can't let go of any error. If a correction error occurs, it will not only waste valuable production time, but also attack the confidence of users. In that case, why should Remote Proofing users buy a proofing program to calibrate remote digital printers

HP's new printing device is a color managed proofing solution that allows users at remote locations to calibrate their digital printers without purchasing or installing color proofing programs. With the help of the built-in spectrophotometer, the host software system can complete all the work

color conversion

in today's American market, most printing plants do not produce according to industry standards. Because of this, it becomes very difficult to prepare and print sample sheets according to the color space of the printing machine, unless you know which printing machine this living piece will be printed on and can obtain the characteristic description document of the printing machine

another method is that the printing machine prints according to the same standard, and then prepares all printing documents according to this standard. However, we all know that every printing press has its own characteristics, so this is not an ideal solution. Are you willing to produce a sample that meets the standard, and then hand it over to the printer operators for color tracking, or are you willing to create a proofing color space suitable for all printing machines in China that not only needs to return to the modern trend

in fact, neither of the above two options is the best solution

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