4 Printing Machines - Printing Materials - The relationship between printing inks is the same as above, which is the most variable factor in the color management process. Controlling the printer is much easier than controlling the printer. The most important function of proofing is to be able to preview the final product. Figure 2 shows that in the digital proofing process, the printer's characteristic file and the printer's characteristic file are indispensable. The two characteristic files must reflect the actual color characteristics of the two outputs! Some prepress companies do not consider the actual printing, and print out some samples that have bright color and cannot be realized in production; some companies have changed their production conditions (such as paper, printing presses, ink, etc.) and do not make new characteristic documents. . It can be said that the problems that arise in the practice of using digital proofing are mostly related to this.
5 PS-RIP is required because Postscript is the actual standard before printing and it is the basis for using the profile.
6 Use spectrophotometer and profile creation software to create profiles and control quality. This requires that prepress (business) and printing (business) are more closely integrated than ever before. The software and hardware for making ICC profiles are expensive. You can choose to use the feature files provided by the manufacturer or cooperate with third vendors.
7 Ensure that the observation conditions are the same. Digital proofing ink is different from printing ink. The color of proofing proofs and printed proofs looks the same. It is actually due to the same-color different spectrum phenomenon. When the lighting conditions change, the colors of the two cannot be guaranteed to be consistent. The use of the spectrophotometer The color block test uses a built-in standard light source. Therefore, there is a high requirement for lighting when observing sample sheets. The D65 standard light source should be used throughout the enterprise.
3 Quality Standards for Digital Proofing Systems
There are three main criteria for judging the quality standards of a digital proofing system:
1 Digital proofing system can print out all colors that appear in actual printing. This means that the color gamut of the proofing system is larger than the print color gamut.
2 Digital proofing system can print the actual printing color correctly. It means that the color difference ΔE ≤ 5.0 between the theoretical value and the actual value of the color of the test strip on the proof sheet. When ΔE = 2.0, the human eye basically does not feel the color difference; ΔE = 3.0, the human eye can just observe the color difference; ΔE = 4.0, if two color blocks are not adjacent, it is difficult to see the two The difference between the two.
3 Digital proofing and stability of the printing press. Its meaning is:
The same color in the sample is constant in different areas: the appearance of the same color is the same in different positions in the same sheet. Inkjet printers do this more easily than laser printers;
The overall performance of the equipment during the formal printing process is stable: the colors of the same batch of products printed out remain basically stable, and large fluctuations are not allowed, ΔE ≤ 5.0;
Stability of the output device (including the press) at any time: The output device should be able to print and print the same file at any time to obtain the same result;
Consistency of output from different devices: If you do not need proofs, but only need to transfer files, you should be able to ensure that the colors of the proofs in different places are consistent;
Sample color stability: The color of digital proofs remains unchanged over time.
In short, using the digital proofing system can fully meet the proof requirements of the machine, but it has very harsh conditions, spectrophotometer is essential for testing, if the digital proofing system is not a complete purchase, the company needs to understand The staff of the color management principle controls and maintains the entire process. (Author: Xu Zhaohui)
Casual Backpack
Mianyang Crossing Cross-Border E-Commerce Co., Ltd. , https://www.wycypets.com