Basic knowledge of the hottest printing II

Basic knowledge of printing (II)

IV. film hanging accuracy

hanging accuracy is generally called hanging accuracy. The higher the hanging accuracy is, the more exquisite the printed product is, but it has a great relationship with paper, ink, etc. If you print a high hanging picture on ordinary paper (newspaper), the picture will not become more beautiful, but will become a mess (terrible). Therefore, before output, you must know what the printing paper of your printed matter is, and then decide the hanging accuracy. General common paper and eye accuracy: imported coated paper or self-adhesive, etc.: imported offset paper, etc.: ordinary offset paper, etc.: line paper: line, and so on. The worse the paper quality, the lower the eye, and vice versa

before prepress output, we must pay attention to the following issues:

1. Select commonly used design and production software during production, such as PageMaker, etc., and try not to use word, etc

2. The mode of the pictures in the text must be CMYK mode, with an accuracy of at least 300*300dpi/pixel/inch

3. Check whether the words in the publication are four-color words. If so, change it to monochrome 100% black

4. If PageMaker, Weisi, founder and illustrator are used, their linked image files must be copied together with the original files

5. Photoshop files should preferably be PSD (unconsolidated layers) files to facilitate modification

6. Try to use common fonts, such as founder and wending. Try not to use rare fonts. If it has been used, CorelDRAW and illustrator first convert the text to the outline mode, which can avoid the problem that the output cannot be output because there is no such font in the output center. If there is a supplementary document, it must be copied together

7. Clearly inform the output center of the finished product size, printing volume, and usually pay more attention to the printing paper, so as to facilitate the assembly and hanging

8. If the contents of the two pages are the same, but the black text parts are different (often encountered), then you only need to output the CMYK four colors on the first page and the K color on the second page, so as to avoid waste and save money. If there are only two colors (such as red and black) and the printing requirements are not high, it is only necessary to output them in the same color plate at the same time, and there is no need to divide them into two colors for output. You can deal with it when printing and plate making. It also saves money

point angle

Green: 15 degrees Red: 75 degrees yellow: 90 degrees Black: 45 degrees

the general performance cannot be compared with that now. The arrangement of points is neat, and the market momentum of plastic film is positive. Therefore, there will be angles in application. For example, in monochrome printing, the line angle is mostly 45 degrees, which is based on the points printed at this angle. It is visually most comfortable and difficult to detect the existence of points, resulting in the effect of continuous gray tone. As for printing with two or more colors, we should pay attention to the combination of two angles, otherwise unnecessary patterns will be produced, which is called moier. Generally, if the angle difference between the two is 30 degrees, there will be no collision. Therefore, generally, for two-color printing, 45 degrees will be used for the main color or dark color, 75 degrees will be used for the light color, and 45 degrees, 75 degrees and 15 degrees will be used for the three colors respectively. If it is a four-color printing, 75 degrees will be used for the red color, 90 degrees for the yellow color, 15 degrees for the green color, and 45 degrees for the black color. These perspectives are not limited, but changed according to different needs

what is postscript

postscript is a programming language specially designed for printing graphics and text. It has nothing to do with the printing medium. Whether you print on paper, film or screen display, it is suitable. It is a page description language, similar to HTML

postscript was proposed by Adobe in 1985. It was first applied to Apple's laserwriter printer, which is the main reason why it is difficult to accurately determine the shrinkage rate. The main goal of postscript is to provide a device independent language that can easily describe images. Device independence means that an image does not need to be described with the help of any specific device characteristics (for example, the resolution of the printer), so this description can be printed on other Po stscript printers without any modification

postscript, as a language, has a complete set of grammar and format regulations. If you are interested in this aspect, please browse the website of a Dobe company. Adobe company has very comprehensive information

postscript files are stored as text, similar to HTML files. You can see this by opening a postscript file with WordPad, as shown in Figure 1. The postscript file itself only uses postscript language to describe the characteristics and parameters of the image to be displayed or printed. When displaying or printing the postscript file, the postscript interpreter interprets and executes it, prints or displays it specifically, and obtains the desired image. Figure 2 shows the postscript file in Figure 1 in the postscript file reader. You can see that the postscript file is interpreted and displayed, and the color page is obtained. Compared with other formats of files, postscript files have many advantages, and the device independence mentioned above is a very important point. Postscript files also have the advantage of being independent of * as the system platform. Because many UNIX graphics environments take the support of postscript as a core part, whether you use windows* or unix* operating system, you can read and print p ostscript files, which is more convenient for communication. Because postscript files are stored as text, they are relatively small and suitable for transmission on the Internet. In addition, printing and display on postscript devices (printers, monitors) have unique advantages, which can achieve the best effect

there are several ways to generate postscript files:

(1) you can refer to the language format of postscript and write a postscript file directly with a texter as needed. Of course, if the file is complex, the workload is not small, and you have to be familiar with the syntax of postscript

(2) you can use special postscript file software or functions provided by some text and image software to generate postscript files

(3) another simplest method is to add a postscript printer (virtual) to your * production system, and then print the image you need into another file through that postscript printer in the writer or grapher. The file you get is the postscript file you want

printing process

prepress refers to the work in the early stage of printing, generally refers to photography, design, production, typesetting, film production, etc

printing refers to the work in the middle of printing, and the process of printing finished products through the printing machine

post press refers to the work in the later stage of printing, which generally refers to the post-processing of printed matter, including cutting, laminating, die cutting, pasting bags, mounting, etc., which is mostly used for publicity and packaging printed matter

printing elements

paper: there are many types of paper, generally divided into coated paper and uncoated paper. Coated paper generally refers to coated paper (glossy copper) and matte paper (matte copper), which are mostly used for color printing; Uncoated paper generally refers to offset paper and paper, which are mostly used for the printing of letter paper, envelopes and newspapers

color: generally, printed matter is embossed by four colors: yellow, magenta, cyan and black, and there are also printing spot colors

post processing: post processing includes many processes, such as bronzing, embossing, etc., which help to improve the grade of printed matter