Several points needing attention in PDF printing
at present, with the increasing maturity and improvement of Prepress digital process, more and more prepress production departments receive electronic documents in commercial printing. Pdf files are the most common of these electronic files, which are standard and stable unit files that conform to printing. Of course, there are also files packaged by typesetting connection scatter, such as founder Feiteng, quark, PageMaker, InDesign, etc. In addition, PS and other document formats are also the original documents often encountered by printing plants. Moreover, some of these electronic manuscripts often carry customers' digital manuscripts or sample books. Generally speaking, the prepress production department of the printing factory will sort out these different kinds of document formats and make them into common document formats suitable for the prepress process of the factory, such as PS or PDF file format, and then through the prepress workstation, such as founder Changliu, print standardization, color conversion, trapping, typesetting, etc., and finally rip and republish
when there are customer originals, such as digital manuscripts, and the printing color is required to follow the digital manuscripts as much as possible, the pre press inspection of electronic manuscripts becomes particularly important. Now, for PDF or PS files of this standard, use the pre flight check software to check the trapping, image format, trapping, font, image resolution, color configuration file, etc. in the file to confirm that the content in the file conforms to the printing standard
prepress color pre inspection of electronic manuscripts
for electronic documents of different customers with color matching digital proofing originals, will the printing factory print the customer's color manuscripts according to its own printing standards? The effect of color matching is generally to do experiments in high and low temperature boxes. What effect can it achieve? The embarrassment that printing cannot keep up with the full-color manuscript caused by the lack of color pre inspection after machine printing has occurred from time to time. In order to solve this kind of problem, we must pre check the color of the customer's color manuscript. This will be an indispensable part of the whole process of color management in printing plants
to pre check the printing color, the printing factory needs to pre check and proofread or evaluate the color effect of the customer's electronic manuscript in the printing standard or printing state of the factory. In order to facilitate the electronic manuscript and digital typewriting for different customers, the corresponding color processing is carried out in advance to achieve the best color matching. In actual production, customers have different requirements for the color matching of the printing factory. According to the simulatability of different originals, the printing factory can choose different color pre inspection methods. This takes into account both cost and customer satisfaction with color. After all, economic efficiency is the lifeblood of enterprise survival
Epson inkjet digital manuscript is the most common customer manuscript in commercial printing plants. Of course, laser manuscript is also used as printing color tracking. For the uneven quality and effect of the original, as well as its simulated printing effect, if it is not pre proofread and color pre checked, the printing color effect will not be estimated
in many cases, the digital manuscript from customers is bright and saturated in color; Sometimes, the image of the laser manuscript is dim and weak, and the color is gray or color biased as a whole. When you encounter these guest originals, you must pre check their colors. Here is a brief introduction to several methods and common problems of prepress color pre inspection
first, for electronic documents and color tracking digital color manuscript from customers, you can use print out digital manuscript to check the color. However, this requires higher requirements for digital proofing of printing plants. First of all, the printing plant should test the color characteristics of the printing machine according to certain printing standards, such as national standards, swop, gracol, etc., according to certain standard specifications and conditions, and collect the color characteristics of the printing machine under the standard printing state as the printing color characteristics document of the whole printing plant. As we all know, the color gamut space of general display and that of digital proofing without calibration are larger than that of ordinary four-color printing, and the final color effect of prepress image should be achieved by printing color. Therefore, in the pre press color correction, we must choose the color characteristic documents of our factory or close to our four-color printing to pre display or serve as the printing model, which can better withstand the experimental source documents of the majority of consumer users. Such digital proofing is used to pre check the dynamic stiffness and static stiffness of metal parts. It is meaningful and reliable. At the same time, for the digital proofing used to pre check the color before printing, it is necessary to calibrate the color regularly, compare the difference between the digital sample and the printing sample, and follow up the color chasing effect of printing
second, use the screen soft proofing to calibrate the color. This is the most practical and feasible method of color correction. From the test effect of soft proofing, using soft proofing as a printing signature sample is still in the exploratory stage in China, and it needs to be developed to replace digital samples. However, it is still possible to use screen soft proofing to check the color pre inspection of the customer's electronic manuscript under the printing color characteristics of the factory. The premise of this kind of screen soft proofing for prepress color pre inspection is:
1 Customers have high requirements for printing colors, and the colors are as similar as possible
2. For soft proofing, it's best to use an industry certified display such as Eizo. It's still unrealistic for an ordinary display to do soft proofing. Nor can it meet the requirements of pre inspection of color before printing. "As long as it is used properly.
3. The display should be calibrated regularly and evaluated, and the color pre display should be carried out by accurately printing the color characteristic file.
4. When comparing the soft proofing color with the customer's color draft, the ambient light source of the customer's color draft should be measured