HP's "photo hand" application in gravure proofing

In the field of pre-press proofing, HP has been closely integrating market demands, constantly innovating and serving all industries. Recently, the commercial peripheral products division of China Hewlett-Packard Co., Ltd. has introduced a brand new “photorealistic hand” series A3+ format HP DesignJet 10ps/20ps series digital design proofer.

This series of printers is particularly suitable for prepress proofing processes in graphic image fields such as platemaking output centers, advertising design companies, and publication magazines. Moreover, “Photos Hands” is a complete set of color management and output systems, including a new closed-loop color calibration system, color management software, HP special proofing media and ink, and at the same time comply with a number of popular industry standard colors, can ensure The complete program has a complete color management and output, so it has outstanding performance in the proofing field, especially to meet the needs of gravure proofing.

Gravure is not easy to proof

In the current type of printing, gravure occupies an important position. Gravure printing is a relatively simple printing method. The performance of the new gravure printing press greatly exceeds that of the old gravure printing press. The advantages of gravure printing include short machine preparation time, stable performance, wide application of inks and substrates, and simple operation. .

As with other printing methods, gravure should be proofed before printing to control the quality of printing. Gravure proofing plays a very important role in gravure printing. The proofs are the link between the platemaking company, the printing company and the customer. However, due to the variety of materials used in gravure printing, thin touch, aluminum foil, composite materials and Paper or cardboard, which requires gravure proofing must have a high degree of flexibility, and the corresponding equipment and process support.

Gravure proofs are available in a variety of analog and digital formats such as Soft Proof, Bluelines or Ozachrome Proof, Overlay Proof, Single Sheet Proof, Offset Press (Offset Press Proof), Driect Digital Proof and Gravure Press Proof.
At present, the most used proofing method is the gravure proofer proofing method. The gravure production technique requires that the proofs printed by the gravure proofer should be printed by the printing company and the results are basically the same. Therefore, the construction of the gravure proof printer is not significantly different from the gravure printing machine. It is made by simulating the principle of gravure printing machine, and the ink is transferred to the substrate to form a clear pattern through the pressing action between the impression cylinder and the gravure plate roller. The new gravure proofer has been constantly exploring the actual printing process (imprinting form, ink, printing materials, etc.) and has taken a series of improvements and guarantees to reflect the quality of the drum as accurately as possible. D. Therefore, its proofing is becoming more and more common and has developed rapidly in recent years.

Digital gravure proofing echoes

Compared with traditional proofing, color digital proofing has many technical advantages: speed. It can directly output the layout produced by the computer, which reduces the intermediate links of traditional proofing, such as filming, printing, and developing. It can get proofs in a short period of time to improve the production efficiency and meet the time requirements of customers. low cost. Since the proofing can be done before the film is taken out, the consumption of the film and the printing plate is reduced, and even if it needs to be modified, it will not cause too much loss. Small investment. Compared with traditional proofing equipment, digital proofing equipment investment is much lower. Simple operation and strong consistency. The process of digital proofing is completely controlled by computers. There are few human interventions. Only initial settings and periodic adjustments are required. Printing in accordance with the prescribed method ensures that the proofs are completely identical. While traditional proofing is affected by many human factors such as printing, development, inking, and Sheung Shui, it is difficult to ensure the consistency of each sample even if it is the proof of the same batch. The operator's operating level requires high standards. .

Digital printing, direct plate making, digital proofing and digital workflow are the fastest growing areas in recent years. Color digital proofing is the result of comprehensive application of technologies such as computer technology, color printing technology, and color management. At present, there are many domestic digital proofing systems such as BestColor digital proofing system, CGS digital proofing system and Jinhao digital proofing system. The domestic production is mainly the digital proofing system developed by Peking University Founder. All digital proofing systems use the internationally-accepted ICC color management system. The software used to create PROFILE files for the ICC color management system is basically all software.
Heidelberg's PrintOpen and Kodak's COLORFLOW. In theory, the color digital proofing system can use any type of color printer, such as a color laser printer, a color inkjet printer, a color thermal sublimation printer, and the like. However, it is necessary to print at a high speed, but also to meet the requirements of large format and print quality, non-large-format color inkjet printer must be.

Here focuses on the direct digital proofing method. The direct digital proofing machine is also known as Direct Digital Color Proof (DDCP). It adopts ink jet and electronic imaging proofing machines and uses digital technology to directly obtain high thermal transfer materials. Resolving halftone proofs eliminate the need for intermediate film use. This proofing process is fast and subtle, but the range of color rendering is limited. Direct digital proofing has the characteristics of high production efficiency, reliability, convenience, etc. Therefore, some manufacturers have taken the lead in abandoning the gravure proofer for proofing, and have completely adopted digital proofing without film. Undoubtedly, direct digital proofing is the future development trend.

The focus from the computer to the proofs is to check how the results of the digital workflow will be displayed during actual printing, as a technical basis for large-volume printing. Through years of hard work, with the participation of color management systems, digital proofing results have become more and more close to traditional gravure printing.

At present, as China's largest share of the printing market is offset printing, digital proofing technology first breaks through offset printing. Beijing has already appeared pre-press companies mainly based on digital proofing, and its business volume is still growing. For example, Shangpin and Shenglanhong show that digital proofing technology has been accepted by the printing industry. At present, dozens of direct plate-making systems have been introduced in China. Digital proofing equipment is a necessary part of the digital proofing system. It is expected that with the popularization of direct plate-making techniques, digital proofing technology will develop rapidly in the field of offset printing.

However, the digital proofing technology is not only applicable to the field of offset printing, but also applies to the direct plate making, gravure printing, flexo printing and other printing methods. Moreover, it should be said that gravure proofing is more difficult, the cost of plate making is higher, it is more likely to cause rework, and the losses caused by rework are also greater, so it is more urgent to solve the problem of digital proofing. Gravure printing is mainly used for packaging and printing. The law of color reproduction is different from that of offset printing. It has some special features, and it often uses spot color printing, which requires higher color proofing and more difficulty. It may be very difficult to completely simulate the proofing effect of gravure. There are still some technical problems that need to be solved. However, if you can simulate 80% proofing work and reduce one or two scraps in actual work, digital proofing can be obtained. Very good economic benefits. It can be said that for gravure, the digital proofing method provides a very good solution.

The Application of "Writing Hands" in Gravure Printing Proofing

Hewlett-Packard Company has been committed to the popularization and promotion of commercial printing in various fields. In the most direct printing industry with graphics and graphics, HP more specifically focuses on the accuracy, stability, and high-speed of pre-press proofing. Compared with other brands and other types of digital proofers, HP's “Photography Hands” has superior performance in proofing performance. Therefore, it is practically applied in gravure printing.

“Fashion Hands” allows the printer to achieve a color standard defined under specific conditions through a closed-loop color calibration system, with a minimum ink droplet size of 4 picoliters. HP color grading technology and a 6-color print head provide a wider range of colors, while The reduction in granularity achieved and the smooth color transmission, in general, these features ensure the accuracy and realism of the high-quality picture output and proofing color of 2,400,1200 dpi image speed. The "Photo Man" series adopts advanced thermal inkjet (TIJ) printing technology, uses six color print heads, each color print head includes 304 printing nozzles, and uses HP's unique JetExpress printing technology to further speed the production of proofing. At the horizontal level, it only takes 4 minutes to print the image of 13`X19` in the best mode. The "Photo Manipulator" uses HP Remote Proofing Software to allow users to create a complete set of documents containing data content, color outlines and print settings, and transfer them anywhere via electronic documents in PDF or JPG format. The receiver only needs to have another “photorealistic hand” to securely receive files while ensuring the consistency of color transmission, storage, and output. The "Photo Manipulator" is equipped with a modular ink system to meet the needs of large and repetitive proofing. At the same time, in order to match the special nature of proofing media, there are three proofing media to choose from, including high-light proofing paper and matt proofing paper. Matte proofing paper. The price of finished products that are proofed with “photos hands” is estimated to be nearly 1/3 cheaper than traditional proofing.
The Prospect of Digital Proofing in Gravure

Gravure is mostly used for packaging printing, and the printing medium is often plastic and specialty paper. The color of the substrate changes greatly. Using dedicated printing paper to simulate the color has certain difficulties. Therefore, it must first be able to simulate the basic color of the substrate. Second, there are many types of spot colors used in packaging and printing, and the problem of accurately printing spot colors must be solved. In the final analysis, the basic problem of how to use digital proofing to accurately simulate printing conditions and colors. Therefore, if digital proofing technology is to be popularized in packaging and printing, it is necessary to focus on solving the problem of changing colors, and to provide users with a simple means of setting colors and simulating spot colors, and providing operators rather than professionals. The operating environment.

On the other hand, the current offset printing platemaking technology and production process are the most mature, the highest degree of digitization, the most standardized data, you can get the print control parameters directly from the prepress data. For offset printing conditions, technical services can be completely provided by equipment suppliers and specialized service agencies to perform color correction and other standard operations. In contrast, although gravure printing also uses computer-based plate making, the digitization process is relatively lacking, and the human factors in the printing process are still very large. For example, the ink preparation and the printing material conditions have a great influence on the printing results. Printing conditions The stability directly restricts the application of digital proofing. Therefore, digital proofing should be applied in gravure printing. First, the problem of printing stability should be solved.

Despite many difficult factors, as discussed earlier, digital printing with the HP DesignJet 10ps/20ps “hands-on-hand” printer as the main equipment is very urgent due to the high cost of gravure plate making, the difficulty in proofing, and the possibility of rework. , And many gravure printing plants have adopted digital proofing methods more or less in actual production to check the intermediate results of the production process. If the means of digital proofing can be improved, some special issues in packaging printing can be solved. The packaging industry will be very welcome and will be popularized in the packaging industry very quickly.

Reproduced from: eNet