Digital proofing basics Q&A (8-11)

8. Q: How does the proofing paper used in digital proofing affect the proofing 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.

9. 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, OutputPrOfile should be established.

(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.

10. Q: What is the 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.

11. Q: What is RIP after proofing? What are the characteristics?

A: After RIP, the proof is usually the index code. RIP will output the 1-BitTiff 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. 1 - BitTiff file contains all the information of the output layout, including all the information of the text, layout, images, graphics and the printing network structure (points, dot shape and angle), so the output digital proofs are most faithful to the final printing. effect.

However, due to the huge data volume of 1-BitTiff files, the software and hardware requirements are very high during the actual production and application process. The processing time of current digital proofing technology will be several times or even more than ten times that before RIP proofing. The actual production efficiency is low, and users are used. less. With the improvement of computer computing speed and printing speed and the improvement of digital proofing RIP, this problem will be better improved.