The hottest way to talk about prepress output

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Talk about the ways of prepress output

at present, there are many ways of image and text output, including computer to proof (digital proofing), computer to film (computer output film), computer to plate (computer offline direct plate making), computer to press (computer on machine direct plate making), computer to paper/print (digital printing), etc

generally, proofing is divided into digital proofing and analog proofing after the production of printed pages. Simulation proofing is also called mechanical proofing. Its essence is simulation printing, which is to install the printing plate on the proofing machine to print and get the sample under the condition of imitating the printing conditions (such as paper, ink, printing method, etc.). The workflow is generally as follows: image and text output technology (get the original version), drying the printing plate, simulating the production of proofing and signing the printing plate

the purpose of proofing is the following aspects: ① the inspection sample of prepress work is mainly to check the quality of the original. For example, whether the reproducibility of the original tone and color meets the requirements; Whether the layout size, image, text arrangement, rule line, etc. are correct, whether there are omissions, etc. if there are any defects, they should be corrected. ② The reference sample of printing mainly provides samples or basic parameters of printing for formal printing, such as ink color, point reproduction range, etc., so as to achieve standardized and standardized printing operation. ③ As the signature of the customer, it is mainly to provide the printing sheet to the customer. If the customer approves, he will sign on the printing sheet for printing. Otherwise, the printing enterprise will have to revise it again

due to a series of defects such as complex process, high cost, long production cycle and great influence of human factors, analog proofing is gradually retreating from the stage of history, and more and more printing enterprises use digital proofing technology. The so-called digital proofing is to output the page (or print sheet) data produced by the color desktop system directly through the color printer (inkjet, laser or other means) without any form of simulation means, so as to check the image page quality of the prepress process, provide reference samples for the printing process, and provide users with the basis for signing and printing

the usual digital proofing system mainly includes two parts: color management system and output device. There are many kinds of output equipment used in digital proofing system, including heat transfer output equipment, thermal sublimation output equipment, inkjet output equipment and laser output equipment. The color management system includes two core technologies, postscript interpretation technology and color management technology. The postscript interpreter is guaranteed to use 5 The documents of the experimental slot can be correctly explained, and the color management technology can ensure that the color of the sample output of carbon materials including graphene, fullerene, carbon nanotubes and carbon fibers is consistent with the color of the printed output. At present, there are many common color management software, such as bestcolor digital proofing software of German best company (which has been acquired by EFI), blackmagic digital proofing software of Australia Malaysia's star proof digital proofing software and Germany's GMG company's digital proofing software

the prepress process flow of enterprises using digital printing is as follows:

the digitization process of originals, image and text processing technology, digital proofing technology, signature image and text output technology (output film or direct output plate)

how to choose your own digital proofing system? Generally speaking, when investigating the digital proofing system, two aspects are mainly considered: first, the technical indicators of the digital proofing system itself in color reproduction and print quality; Second, the effect of matching printing and its adaptability to printing production. As far as the products listed above are concerned, different software has their own characteristics. For example, the best color digital proofing system is the most widely used digital proofing system in China at present, which enables general inkjet printers to also have the ability to output digital proofs with good quality. However, due to the defects of ICC technology, if the output parameters are set incorrectly during proofing output, it will not be output. In addition, there are also deficiencies in gray balance reproduction. While the blackmagic digital proofing software in Australia only controls the spot color field when dealing with spot color, the effect of selective color correction function is not ideal, and the control of hierarchical curve is not very accurate. Malaysia's star proof digital proofing software corrects the color by adjusting the density. The value of the color difference △ e between the color adjusted by star proof software and the printing color is about 1.8. The processing function of 1-bit TIFF file is powerful, and it can output images with 200lpi accuracy. However, it requires operators to have a good understanding of color. German GMG's digital proofing products are excellent in single black, spot color and dot proofing. Therefore, when choosing digital proofing products, users had better consider comprehensively according to the specific needs of the enterprise and the characteristics of each software

when choosing a digital proofing system, in addition to choosing a digital proofing software, you also have to choose a digital output device. Color laser printing in digital output equipment can also be used in film, toys, clothing, utensils, electronic manufacturing and thermal transfer/thermal sublimation printing. Due to the high cost of equipment and printing, it has not been widely used. The accuracy of color laser printing output cannot reach the accuracy of printed matter, so at present, it is rarely used in the field of digital proofing; Color inkjet printing is the main product for digital proofing. At present, there are two types of inkjet printing, thermal foaming inkjet printing technology and micro piezoelectric technology. Thermal foaming inkjet printer is to instantly heat the thermistor to expand the ink droplets in the launching boring to bursting, so as to launch the ink. As the chemical composition of ink changes at high temperature, the color stability is relatively poor. In addition, this type of printer nozzle is a vulnerable part, so the printing quality has a change process from good to bad. It is very difficult for equipment using this technology to maintain the stability of color. Micro piezoelectric technology inkjet printing uses the change of voltage to make the ink shoot out from the nozzle. Its nozzle is a solid part, which fundamentally ensures the stability and consistency of color, and can meet the requirements of digital proofing for output equipment, while greatly reducing the output cost. Micro piezoelectric technology is a patented product of Epson company. Using intelligent ink drop transformation technology, the minimum output ink drop can reach 4ppl, so as to meet the requirements of fine dots of printed matter, and the image and text are clearer

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