The meaning and technology of digital proofing

Digital proofing is a new technology, and we hope that the question and answer form we adopted will let everyone know about it.
Q: What is the meaning of digital proofing?
Answer: Instead of using ink to print proofs on officially printed paper, proofs are printed on synthetic carriers with pigments or other pigments. Digital proofing systems use a wide variety of printing technologies, including thermal transfer technology, thermal sublimation technology, ink technology, and laser technology.
Q: What is the core technology of digital proofing?
A: Digital proofing requires interpreting the user's submitted job, and realistically simulates the printing effect on the printing device. Therefore, the core of digital proofing technology should include two parts: one is Postscript interpretation technology, and the other is color management technology. The Postscript interpreter guarantees that the user's file can be interpreted correctly and is exactly the same as the final output film or media. Otherwise, there will be differences due to inconsistencies in the interpretation results between the proof RIP and the photo RIP; the color management technology can ensure the output of the game. The result is consistent with the color of the printed output.
Q: What are the advantages of digital proofing?
Answer: (1) The stability of digital proofing is very high. Different operators print the same file at different time periods. As long as the ICC parameter settings are the same, the color difference of proofs will not be felt within the visual range. The color adjustability depends on the configured color management software, and the quality depends on the printer's hardware parameters such as resolution, drop size, and so on.
(2) The advantage of digital proofing is that it can simulate a variety of printing characteristics to some extent. As we all know, each printing method has its own characteristics. Different printing manufacturers with the same printing method have their unique technological features. Digital proofing can simulate different printing effects on a digital proofing machine.
(3) The digital proofing speed is very fast. Samples of one A3 format are generated from the file to the printing. It takes about 10 minutes or even faster. This is mainly related to network speed and computer configuration.
(4) Environmental protection and non-pollution are another advantage of digital playing.
(5) From the current market situation analysis, the cost of digital proofing is lower than traditional offset proofing.
Q: What is the difference between analog proofing and digital proofing?
Answer: (1) The simulation proofing needs to use the film to print proofing, and the digital proofing directly sends the data file to the printer to output proofs.
(2) The analog proofing is the same as the film, PS plate, and paper used for printing. Therefore, the reliability is high; the reliability of digital proofing depends on whether the proofing is consistent with the RIP used for plate making.
(3) Simulation proofing is greatly affected by human factors. Proofs on the same film may not be exactly the same. However, digital proofing is digital imaging, with high stability and consistency.
(4) Both the simulation proofing and the printing use the ink, and the color of the two can remain basically the same, but the color gamut of the digital proofing ink is generally larger than the color gamut of the printing ink, so the color range embodied is wider, more vivid and lustrous, often Making printing difficult to catch up.
(5) The simulation proofing uses amplitude modulation network points, and digital proofing uses more frequency network points because the digital proofing system of AM network points is expensive and the cost of proofing is high.
Q: What are the quality and technical standards for digital proofing?
A: There are two main technical standards for quality of DaChanQiang: On the one hand, it is the technical index of the digital proofing system itself in color reproduction and print quality; the other is the matching printing effect and the adaptability to printing production.
Q: How does the printing equipment used for digital proofing affect the quality of proofing?
A: The good loop of the ink jet printer print head will directly affect the output of digital proofing. The print accuracy that can be achieved by the print head determines the output accuracy of digital proofing, and the low resolution printer cannot meet the requirements of digital proofing. The lateral accuracy of the printer is determined by the print head distribution. Vertical precision is affected by the stepper motor. If the paper is not well fed, it will affect the printing accuracy. Horizontal stripes may appear when printing, and the print head may need to be corrected if necessary. When the print head is clogged in the production process, a broken line will appear on the proof sheet. At this time, cleaning the ink head can eliminate this phenomenon.
Q: How does the printing ink used for digital proofing affect the proof quality?
A: The printing ink plays a decisive role in the restoration of the proof color. Inkjet printer inks are pigmented and dye-based. Pigment inks are not easy to fade, and their ink primary colors are more similar to printing inks, but the light source environment has a more pronounced effect on proof color. Dye-type inks have lower costs and have a broader application range for Daxiang.
Q: How does the proofing paper used for digital proofing affect the proof quality?
Answer: The paper used for digital playing is generally imitation copperplate printing paper. On the one hand, it has similar color performance to printing coated paper, and it is easier to achieve the same effect as printing color; on the other hand, it has suitable ink for printing. Coatings and coatings will affect the performance of the proofs in terms of color and accuracy. At the same time, the ink absorption and stiffness of the proofing paper will also affect the proofing quality.
Q: Why do you have to implement color management for digital proofing?
A: Because of the distance and difference between digital proofing, analog proofing, and printing color, the color matching of digital proofing should be completely matched with the printing.
(1) Since digital proofing generally uses special paper, it is more white than printing paper, and the variety of paper and ink used in color printing is large. Dots increase, color range and effect, and four-color dot overlap density vary, so digital Proofing results and different paper, ink and printing methods should be established.
PrOfile file.
(2) Due to the wide variety of digital proofers, such as inkjet, thermal sublimation, thermal transfer, etc., the colors of the same color file output are different, the color appearance is very different, and the color management needs to be implemented to make the difference. The digital proofing effect corresponds to the printing color.
(3) The color gamut of digital proofing is different from that of analog proofing. Generally, it is larger than the simulation proof color gamut. Therefore, it is necessary to map the colors outside the gamut to the gamut that simulates playing.
Q: What is proof before RIP? What are the characteristics?
A: At present, the digital playing in the market is based on RIP proofing and RIP proofing.
RIP proofing is an index code proofing RIP directly interpreting an electronic file (usually a PS file), and under the control of the color management, a print proofing process conforming to the printed matter is obtained on the printer. Digital proofing adopting this kind of technological process generally adopts FM network printing. Images, graphics, and text information can be accurately reflected, but can not accurately reflect the final output RIP results and the structure of the printing network.
Its advantages are: high speed, relatively mature application technology, and low requirements for hardware and software. It is mainly used in design proofing, pre-press proofing and partial contract proofing. It is a digital proofing process that is currently used more frequently.
Due to the multiple RIP multiple output or the same RIP multiple output method, this kind of process requires digital RIP and RIP to have good compatibility with the final output RIP, which requires high technical level for operators.
Q: What is RIP after proofing? What are the characteristics?
Answer: After RIP, the proof is generally an index code. RIP will output the 1-Bit Tiff file generated after the final output of the RIP (that is, the Tiff file after the network is connected). Under the control of the color management, it is consistent with the printed matter on the printer. The process of printing proofs. The 1-Bit Tiff file contains all the information of the output layout, including text, layout, images, graphics, and all the information of the printed dot structure (line dots, dot shape and angle). Therefore, the digital proofs output based on this are most faithful to the final. D.
However, due to the huge data volume of 1-Bit Tiff files, the software and hardware requirements during the actual production and application process are very high. The processing time of the current digital proofing technology will be several times or even more than ten times that before RIP proofing. The actual production efficiency is low. Less users. With the improvement of computer computing speed and printing speed and the improvement of digital proofing RIP, this problem will be better improved.