Pre press question and answer (Part 2)
What are the commonly used color representation methods in computer? Generally, what is the best method to define color
answer: no matter on the computer or in printing, we need a way to describe different colors. In chromatics, the color representation method is also called color model or color mode. There are many types of surface color models, each of which can describe color from different angles, but different color models are suitable for different occasions, and the accuracy is different
computer surface color modes are:
1, RGB mode:
also known as RGB color space. It is a kind of color light mode, which is widely used in our life, such as TV sets, computer screens, slides, etc. all use light to show color. It is often necessary to scan images in printing and publishing. When scanning, the scanner first extracts the RGB color light information on the original image. RGB mode is a kind of additive mode. Through the radiation of R, G and B, it can be described that Chinese plastic machine enterprises have expanded their exploration of emerging markets of extruders in recent years. When the computer defines the color, the value range of R, G and B is 0, which means there is no stimulus, and 255 means the stimulus reaches the maximum value. R. When G and B are all 255, white light is synthesized, and when R, G and B are all 0, black light is formed. This mode is often used when displaying color definitions on the display screen. Images, such as those used in TV, slides, networks and multimedia, generally use RGB mode
2.cmyk mode:
also known as CMYK color space. CMYK is the most familiar to those engaged in the printing industry. This mode is a subtractive mode, which follows the mixing law of subtractive method. CMYK mode essentially refers to the size of C, m, y and k points printed when reproducing color, so the value range of C, m, y and K is 0% - 100%. Co%mo%yo%ko% means white, c100%m100%y100%k100% means black
3. HSB mode: hue, saturation, brightness mode
since RGB images are better displayed and have more beautiful colors than CMYK images, can RGB images be directly output? What are the consequences of doing this
answer: because RGB has a larger color gamut than CMYK, some colors can be displayed on the screen, but the four-color ink can't print as expected. If you want to know the consequences, just try it. Due to the difference of rip, the RGB image on the color separation film may only have the image on the black version, and there is no image on other color versions. It may also be that the information (points) of the image on the four-color film are exactly the same, that is, the equivalent gray-scale image. Although some hair arrangement software or rip can convert RGB into CMYK, it is best to use scanning software or Photoshop for mode conversion
save the color map as DCS format. There is a map when printing black-and-white copies, but there is no map on the output film. Why is this
answer: storing pictures in DCS format will generate five files in the latter half,
what is rip? Why do people like to use software rip now
answer: Rip is the abbreviation of raster processing, which refers to the software or hardware card that interprets postscript coding as dot matrix images in the phototypesetting system. It is generally called raster image processor. It plays an important role in the color publishing system. Its function is to quickly interpret the produced page as a command that can control the output lattice of the laser recorder. It can automatically convert the text, graphics, images and other elements in the page into digital lattice information, and then use these information to control the output equipment to record, so that its work is off or on
the upgrading of hardware rip requires complex technology and a long time, which cannot adapt to the rapid development of software technology; The software Rip is widely used because of its fast update, high processing quality, high speed, and the ability to display the processed results. And a software Rip can drive multiple imagesetters at the same time, with strong networking function
why not set the resolution in typesetting and graphics software
answer: Typesetting graphics software is object-oriented software. The representation of text and graphics is expressed in algorithmic language. The objects produced are independent of resolution. They are output with the resolution of the output device. If the resolution of the output device is high, the resolution of the graphic output of the production page is high. Therefore, graphics software and typesetting software do not need to set the resolution. The lattice information of the original image should be read when the image imported in the typesetting and graphics software is output, which is related to the resolution of the original image
how many types of text are there in CorelDRAW
answer: CorelDRAW divides text into two different types, one is WordArt text, the other is paragraph text. Although these two kinds of text are created using text tools, they have different characteristics. WordArt text has more characteristics of graphic objects, which can apply more special effects to WordArt text; Paragraph text can use more text formats. Based on the different characteristics of these two texts, they can be used for different purposes. If you only need to use a small amount of text or apply more formatting to the text, such as short titles and descriptions, you can use fine art text; If you need to deal with a large number of words and apply more formatting, such as newspapers, brochures, etc., you can use paragraph text. Q & A about AI:
Q: how can I import the figures and tables in wold into AI
answer: if word and coreldraw8 are installed on your computer. 0 that's OK, in coreldraw8. Insert 0 into the new object, import the word file, and then import AI. Or use the PDF writer printer to generate PDF files, and then use the touchup tool in acrobat to call the illustrator page, which is OK. Opening it directly may cause confusion. However, if you use some fonts such as wending, it will still be messy. Or you can paste the document in word into CorelDRAW, then ctrl+x, select Paste in the menu, select paste picture, and then export the document in word to AI format
35 ask: what is the preferred format of EPS software? Why does this format only display a box when imported into freehand (I don't know if there is any problem with printing) but can be displayed in PS. Who can explain the characteristics of this format? Answer: EPS is one of the PS (postscript) formats. It is mainly a standard exchange or output format in prepress operation. Its feature is that it can maintain the respective characteristics and positions of dot matrix image, vector graphics and curve text in the original document. In some software, EPS file can only display a picture frame or a very rough image, but it does not affect phototypesetting output and printing on PS printer. The full name of EPS is embedded postscript (embedded PS file). Postscript is a print description language developed by Adobe company. Like other programming languages, it can be programmed with any texter. The file itself is a text file, which can generally be generated by printing into a file with a printer. You can go to Adobe station to have a look. PS has become the de facto standard of the printing industry
Q & A about PM is also widely used in finished product inspection and single 1 material index test:
Q: Yes, so some standards of the experimental machine are different from other machines. Is it not to make a transparent background in PS and then save it in TIF format? Why do I import PM with white edges? Hurry! Help me
answer: when printing Photoshop images or placing them in other applications, you may only want to display a part of the image. For example, you might want to print or display foreground objects and exclude their rectangular backgrounds. The image clipping path allows you to separate foreground objects and make the external area of the object transparent when printing images or placing images in other applications. This allows you to place images in other files without darkening the background of other files. Store path as image clipping path: 1 draw and store path or convert existing selection to path. (that is, you can only use the path tool to dig. Remember to name the path after it is drawn, otherwise you can't use the clip path.) 2 select the clipping path from the path palette menu. 3 for the path, select the path to store. 4 in order to make the effect of most images better, make the flattening value null, so that the default value of the printer can be used to print the image. If you encounter a print error, enter a new flattening value. Values can range from 0.2 to 100. In general, it is recommended to set the flattening value to 8 to 10 for high-resolution printing (1200 DPI to 2400 DPI) and 1 to 3 for low-resolution printing (300 dpi to 600 DPI). The postscript interpreter creates curve segments by linking a series of line segments. The flattening setting of the clip path determines how close the straight line segment is to the curve. The lower the flattening value is, the more lines are used to draw the curve, and the more accurate the curve is. Press 5 o'clock. 6。 Just store your TIF pictures
question: how to insert a table in pagemaker6.5
answer: generally, use the self-contained table 3.0 to copy all the tables, press Ctrl and e to paste them, and then put them in to see if it is OK. If the self-contained table software of PM is not available, the stupid way is to draw by hand in PM. In addition, it's OK to use CD (export 300dpi and then put it into PM) remember not to delete the CD format in case it needs to be changed
ask: if you can't make gradients and shadows in PM, what methods can you use to achieve the effect of gradients and shadows in PM faster and better? A: the current PM Version (6.5) does not have these functions, but it is not certain that the advanced version will have them. In fact, we can do these effects in PS, save them as TIF, and then put them into PM. Of course, we can also do them in CD, but the gradients made in vector graphics software will have ladder status in printing. Only saving them as pictures can solve this problem. There are too many restrictions on PM, Adobe InDesign can solve these problems
ask: how to open the file of PageMaker 6.5 traditional Chinese version of MAC machine on PC A: first use TRansmac to convert Apple files into PC files, and then don't mention it.
Q: I put the EPS diagram output from ai8 into pm6.5, and then the display and printing are mosaic. How can I use an ordinary printer (my Epson photo1270) to correctly print EPS images placed in PM
answer: first of all, the mosaic phenomenon will not affect future printing, and ordinary printers are unable to interpret postscript. So the EPS printed out is mosaic. PM needs to print EPS graphics on ordinary printer (non PS printer), which can only be printed as PDF, and then print the PDF file with acrobat
ask: the color of EPS graphics placed in PM seems to change greatly after printing (color bias)? For example, y100m100 red feels a little red and purple, while drawing a figure in PM to fill y100m100 feels very red. In addition, the pictures (Photos) in EPS graphics also feel light after printing, but the pictures directly placed in PM print very well. I think it is the problem of EPS files. How can I print colors more accurately
answer: this itself is the bug of PM. PM can confirm its own color. The color of pictures in other formats shows an impression. You can observe carefully. Pictures in TIFF format are displayed as if they were placed in PM
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