Does anyone know what is meant by white paper proofs, black and white proofs, and blue paper proofs? Thanks!

Generally in and printing conditions are basically the same situation, (such as paper, ink, printing methods, etc.), the plate with the original tanning, mounted on a proofing machine, printing, to get a sample. Device resolution Also known as output resolution, refers to the number of dots per inch that can be produced by various types of output devices, such as monitors, inkjet printers, laser printers, plotter resolution.

Digital proofing and traditional proofing

Digital proofing technology is one of the popular technologies in the field of pre-press in recent years. The so-called digital proofing, that is, the color desktop system produced by the page (or sheet) data, without any form of simulation means, directly through the color printer (inkjet, laser or other means) output samples, in order to check the pre-press process of the image of the quality of the page, for the printing process to provide reference to the samples, and provide users with the basis of the signatures can be printed.

This digital proofing technology, not simply find the print output color samples, but through the complex color management software, so that the output samples can be reproduced with the supporting printing samples, including paper, ink and printing suitability and other aspects of the match and similar.

For a long time, the effect of digital proofing can be consistent with the simulation of the printing effect, is a variety of digital proofing color management system (CMS) to pursue the main goal. Now the digital proofing system can not only output FM dot structure and continuous tone of the sample, but also can be output with the follow-up of the actual printing of the exact same (dot line number, dot shape, dot angle and dot area) AM dot structure sample. So even if not yet output color separation or printing plate has not been printed, you can see the actual printing results from the sample, including whether there is a tortoise, whether there is a rose spot, etc., really do what you see is what you get.

Digital proofing system can be promoted in the field of pre-press applications, in addition to color, level, clarity, and even dot gain rate and other characteristics of the printing process can be reproduced, but also depends on the system's stability, consistency, output speed, output format size, system investment, the cost of consumables, and so on, many factors, and it is based on this comparison of digital proofing and traditional proofing.

After several years of development, digital proofing system output printer hard performance and supporting digital proofing color management system as well as RIP, there are significant improvements. Especially this year, the digital proofing system in the breakthrough output speed bottleneck, which should be the beginning of the real popularity of digital proofing technology in the field of pre-press in China.

What are the characteristics and advantages of digital proofing technology compared with traditional proofing technology?

1. Color image reproduction performance

Color image reproduction performance, including images (including lines of text) of the tonal range (also known as contrast), field or saturated color density or chromaticity, gray balance, the level of the curve of the reproducibility (including bright tones, midtones, dark levels of reproduction and network expansion rate reproduction as well as delicate texture and so on.

Whatever color management software, through the measurement of the standard file color block to simulate the printing and the standard file color block of the printer, respectively, to get the ICC format data, the color management system software calculations, the establishment of the proofing process required for the characteristics of the calibration file profile. Data), as long as sent to the digital proofing system, will be able to output and subsequent printing to match the proof sample. Regardless of what kind of paper for printing (such as coated paper, offset paper or newsprint, and even plastic, cardboard and other substrates), what series of inks, digital proofing system can be simulated. If a variety of different digital proofing system in the proofing quality there is a slight difference, which mainly reflects their supporting color management software performance differences.

Traditional proofing technology, due to the proofing machine in the speed, pressure, embossing method are different from the actual printing, so the traditional proofing is difficult to simulate the actual printing, printing is also difficult to catch up with the traditional proofing effect, and digital proofing samples in actual use, press operators generally feel easier to simulate, this is due to the digital sampling and printing in the entire color space in the color difference between traditional Proofing and printing between the color difference.

2. image resolution

As the digital proofing system usually use inkjet or laser printing technology, the general output is the FM dot or continuous tonal structure, so as long as there are more than 600dpi output resolution, the proofing of the sample can be achieved by 150lpi of the effect of the FM dot. Now most color printers can achieve such image resolution.

The new generation of digital proofing system RIP can be output with the actual printing effect of the same AM dots, so the printer is required to have a higher resolution. At present, EPSON inkjet printer output resolution up to 2880dpi, HP inkjet printers up to 2400dpi, the output and the actual resolution of the effect of the same AM dots image, there is no problem. Of course, from the actual dot structure, the sample on the edge of the dot is not as clear as the actual printing of the dot, only with the mesh can not see this subtle difference, people need to be the entire image of the visual resolution and printing the same can be.

Traditional proofing may not be allowed due to overprinting caused by image clarity, and digital proofing does not exist overprinting problem.

3. sample output stability, consistency

No doubt, because the digital proofing system is a digital page file sent directly to the proofing system, in the output of the sample before, all by the digital signal control and transmission, so no matter when the output, even if the time is weeks, months or even years apart, the same electronic document output is completely consistent. Of course, this stability is the premise of the color printer hardware performance, such as inkjet droplet size, ink and printing I can maintain a consistent.

For traditional offset proofing technology, in addition to paper, ink, PS version should remain stable (in fact, it is very difficult) as well as the state of the mechanical proofing equipment (such as the plate table "pressure", the paper table "pressure", the height of the blanket and liner, Water roller and ink roller pressure, etc.) should be kept normal, the effect of traditional proofing is also subject to environmental conditions (temperature, humidity), ink. The amount of its uniformity, ink and water balance and many other factors, the proofing process connected to the sample of the field density can not be maintained consistently, not to mention that it also depends on the level of the operator and other factors.

Relative to traditional proofing, digital proofing is almost unaffected by the environment, equipment, technology, and so on, not to mention the influence of the operator, its stability, consistency is very ideal, so the digital proofing system as a network of sampling equipment to use, that is, everyone can use the digital proofing system to output samples.

4. Output speed

For a long time, the output speed of the digital proofing system has been the bottleneck of the popularization of the technology. Until last year, in the market after the emergence of large-format, high-resolution inkjet printers, the output of a large folio (102cm × 78cm) 720dpi samples of the time, the need for more than 40 minutes, which does not include the RIP explanation of the time. Now the same format, the same resolution of the sample output time, there are a variety of models can be completed within 5 minutes, so the sample output speed, much faster than the traditional sampling time (general monochrome proofing machine to complete the four-color large-format sampling time takes about 2 hours). The reason why digital proofing speed significantly faster, mainly depends on the development of multi-nozzle inkjet proofing technology and fast RIP proofing and servers, some proofing servers can simultaneously control four digital proofing machine.

5. Proofing format

In the past, the general high-performance digital proofing system for A3 (octavo) format. With the inkjet printer hardware resolution and speed of the gradual increase in the increase in cartridge capacity, the application of non-stop replacement of cartridge technology, large format output of inkjet printers are endless, there are output width of 1.5 meters above the digital sampling system, a variety of models can simulate a variety of width of the effect of the printing press.

6. System cost

Traditional proofing system not only requires expensive proofing equipment (imported monochrome proofing machine are more than 1 million yuan, the domestic proofing machine also needs about 300,000 yuan), and also need supporting proofing room (more than 50 meters 2), air-conditioning equipment, etc., but also the need to output separations, the holding of the sun version of the support, the proofing cost is very substantial. The digital proofing system hardware only color printer, control computer and supporting RIP and color management software. A large format (large folio) digital proofing system, the current price is not more than 120,000 yuan. Although consumables (such as ink, special printing paper) is still more expensive, but the output of the same format, the same number of samples (calculated as 4), the total cost is still cheaper than traditional proofing. With the reduction of ink costs, imitation of special printing paper promotion, the future will also use ordinary paper after surface treatment in the inkjet printer output, then the cost of digital proofing system may be reduced to a very low level.

At the same time, the digital proofing system occupies a very small space, and does not require strict environmental conditions. As a result of the output color separation, plate, mechanical proofing and other processes, not only greatly shorten the pre-press design, production, proofing of the total cycle, saving a large number of raw materials, but also to avoid once in the traditional proofing of the sample found after the error, rework and cause a waste of man-hours and materials. The digital proofing system can output samples immediately after the original file is modified.

7. Personnel quality requirements

Traditional mechanical proofing (including the plate process) requires experienced, high-quality operators, in the workload is large, but also need to shift change, which will not only bring the proofing sample quality is not stable (the human factor), but also increased production costs. Digital proofing system generally do not need a person, as long as the production designers know how to correctly use the proofing control computer can be. In addition, the digital proofing system can work 24 hours a day, all these are traditional proofing can not be compared.

It can be said with certainty that digital proofing to replace the traditional proofing has become an irreversible development trend.

Traditional proofing and digital proofing technology comparison

Traditional proofing digital proofing relative to the printing effect of the color image reproduction performance is poor, color difference is larger good, color difference is small image resolution is good (overprinting is accurate) good sample consistency of the poorer output speed is slow and fast proofing format can be large or small system costs are higher and lower staffing requirements requirements are high without special requirements other than those required to separate the color film output, Sun plate supporting not required to occupy a large area occupies less environmental requirements of high environmental special requirements