1, plate making, the document should be divided into blue (C), magenta (M), yellow (Y), black (K) four colors, its separation principle is what?

A: The color drawings or color photographs, the number of colors on the screen there are thousands of species. To put thousands of colors to the same color color china printing is almost impossible. Printing uses four-color printing method. That is, first color originals decomposed into green (C), magenta (M), yellow (Y), black (K) four-color color version, and then again when printing color synthesis. The so-called "separation" is based on the subtractive principle, the use of red, green, and blue color filters of different colors of light that has a wavelength selective absorption characteristics, and the decomposition of the original yellow, magenta, cyan primary color. In the separation process, the filter is absorbed by the filter itself up shade shade, as well as on the photosensitive film, a monochrome image is negative, further screening, dot negative form, the final copy, tan color plates. This is the earliest photographic color separation principle.

Since the development of printing service technology, we can now scan through prepress equipment the original color separations, sampled and converted into digital information, which uses the same method with photoengraving decomposed into the original colors of red (R), green (G), blue (B) three colors, and digitized by the computer through mathematical calculations the digital information decomposed into green (C), magenta (M), yellow (Y), black (K) four-color information.

2, prepress image why should we increase network?

A: Because the printing process printing can only be determined using continuous tone dot reproduction of the original level of magnification to see if the chart, you will find is composed of numerous outlets consisting of varying sizes. We see the dot size are different, but have occupied the spatial position of the same size, it is because the original image once after screening, put image is divided into numerous regular arrangement of outlets, namely the continuous tone image information into discrete outlets image information. Larger networks, the performance of the darker, darker level; smaller networks, the performance of the color the more light, the brighter the level of representation. Each network occupies a fixed spatial position size is determined by the number of screen lines, for example, add a mesh network is 150lpi, one inch in length or width with 150 outlets. Dot spatial position and dot size are two different concepts, such as C50% dot size is the meaning of the spatial position of the dot representing 50%, 100% means full coverage dot dot size spatial position, i.e. the printing called " on the ground ", 0% because there is no network, only outlets spatial location, so this place is no ink is printed on. Obviously the larger hanging mesh count, the smaller the dot position occupied space, able to describe the level of the more, the more delicate. In fact, the original levels and color is through this method is reproduced hanging out.

3, what is the process color?

A: printing color that is different from the C, M, Y and K color composition percentage, so called mixed color is more reasonable. C, M, Y, K is commonly used in four-color printing. In color printing, this four colors has its own color version, recorded in the color version of this color outlets, these outlets are generated by the halftone screen, and the four kinds of color version combined together to form a defined color. Adjust color version of Internet dot size and spacing can be formed of other primary colors. In fact, in the paper above the four printing colors are separated, only relative close, due to our ability to distinguish the eyes have a certain limit, so can not be seen. Visual impression we get is a variety of color mixing effect, so have a variety of different colors.

Y, M, C can be synthesized in almost all colors, but need black, because through the Y, M, C resulting black is impure, in the printing to be more pure black, and if using Y, M, C to produce Black ink will appear excessive localized problem.

4, color desktop publishing equipment What? What software?

A: The color desktop publishing system consists of graphic input section, graphics processing unit, graphic output section has three major components. Some of the specific components of each are as follows:

(1) graphic input part of the equipment: scanners, digital cameras, computers. Software: The device driver software, and MAC and PC operating systems.

(2) graphic processing part of the equipment: the computer. Software: 1. Computer Software: Image processing software category as Photoshop, Painter. 2. Graphics class software: FreeHand, CorelDraw. 3. Typesetting software PageMaker, QuarkXpress. JOB-dimensional image system software: 3DS, Infihi-D, Strate-StudioPRO.

(3) graphic output part of the equipment: computers, color printers, laser printers, laser imagesetter, platesetter, red version of the machine, etc., direct digital printing presses. Software: RIP, driver software, font.

5, why computer design system requires the use of large capacity memory? The large capacity memory used have?

A: Design to the use of many photographs or computer-generated images, because the need for printed output, the image resolution is usually high, about 300Dpi. Therefore, the disk space occupied by the image are great. For example, a 4K imposition file, generally all the stored files to more than 100M or more. Usually use 3.5-inch floppy disk can not meet the requirements of storing images, so use to large-capacity memory. The large capacity memory used are: ① Optical disk (MO) drive platters 230M and 460M or greater. ② hard disk activity. ③ ZIP (100M) driver. ④ rewritable discs.

6, prepress design or computer design workflow What?

A: The general workflow has the following basic processes:

① clear design and printing requirements, customer acceptance of information ② Design: including input text, images, ideas, imposition ③ a black and white or color proofreading, allowing customers to modify modify ⑤ ④ Press proofreading proofreading again, allowing customers to modify until ⑥ finalized to allow customers after signing a film ⑦ ⑧ sent prepress proofing press proofing, allowing customers to see if there are problems, such as no problem, customer signature. Prepress design all the work is completed. If there is a problem proofing, have revised and re-output film.

7, computer design system to complete the design of work processes is what?

A: In the design of the system works as follows: ① first press on the final size of the image is scanned originals, and the image in the image adjustment software is good, and can do some creative design work.

② In the graphic or typesetting software for layout design work include: entering text, drawing graphics, placed images.

③ be customers finalized, the document sent to the output center output film. Laser imagesetter is the work of the PostScript language, the RIP (raster image processor) into a bitmap image of the layout description and divided into C (cyan), M (magenta), Y (yellow), K (black) four-color film. If the design requirements are not output the final film, but the large color inkjet kind, use inkjet printers output can be.

8, what is the density?

A: The color of the light phenomenon generally have the object transmission, reflection, selective absorption. Figure 3-20 (color), O is the color of an object, when the incident light energy is Q Pops, selective absorption by the object O. The transmitted or reflected light energy is Q out. The density of the object O: D = lg (Q out / Q in) so that the density of the amount of light absorbed by the object properties. The quantity of light absorbed by the object, and its density is high: a small amount of light absorbed by the object, its density is low. Density is the printing industry to measure the transmittance of film, print color shades of a common physical quantities.

9, how to choose the correct output screen angles?

A: In order to avoid the collision mesh, in theory, should match the color difference between 22.5 degrees, but proved 15 degrees, 45 degrees, 75 degrees and 90 degrees angle of these four works well, yellow version of the visual stimuli weak, visual sensitivity is poor, it is generally set to 90 degrees, the visual angle of 45 degrees is most sensitive to the primary colors of the originals general magenta or green as 45 degrees. For example: For the purposes of the blue and white screen should be set at 45 degrees blue version, for glow of the setting sun on the screen should be set at 45 degrees magenta version, magenta and cyan in a non-45 degree angle can be of 15 degrees, 75 degrees as the black version.

10, file output only after the black version of moldings, the other version is no moldings, how to do?

A: The only way is to re-export, and to the color moldings from 100% BK to 100% C100% M100% Y100% BK, coming into a four-color black color black.

11, fill out a color version and a color version of the original sets are not allowed, how to do?

A: The color version of all the re-export it again. Although this is the most stupid way, but it is the safest way.

12, the output of the film when the membrane is selected or downward facing Shang Hao good? What is the difference?

In the film, when the output is selected membrane facing up or down, depends on the film is a positive or negative may be. When the piece, select emulsion side up or down, have anti-positive film, when the negatives, select emulsion side up, a positive negative film. Because for positives, the film can be directly copy, membrane surface coinciding with the PS version contact proofing effect. For negative is concerned, it must be copied into positives before copy, the copy, the copy negatives is placed on the stage, emulsion side up, above and then stacked copies of films, this film also happens to be copied face contact with the membrane to ensure copy quality. And copying the copy process, the light source is not directly irradiated on the membrane surface catalog printing.

13, what is the laser value? How to adjust?

A: The laser phototypesetting value refers to the size of the laser exposure. It not only determines the size and density of the film on-site software displays dot dot values ​​and imagesetter output values ​​are consistent, but also closely linked with the life of the laser, therefore, imagesetter to choose a suitable laser value in developing and fixing conditions ( temperature and time) under conditions of relatively fixed, the film density D field solid ≥ 4.0, measured at 50% dot percentage is greater than 52%, the values ​​may be appropriate to reduce the laser light; measured at 50% dot percentage is less than 48%, the may be appropriate to increase the laser values ​​increase and decrease the value of the magnitude of the laser should be made of 50% dot percentage error of ± 2% or less. Similarly, when D real <4.0, measured at 50% of the network is greater than 52%, should be appropriately reduced laser value, when the dot at 50% less than 48%, the value should be increased laser . Different types of laser exposure film will be different, so each time you replace film model, the response to the laser value re-tested in the developing, fixing and film are fixed in the case, the laser exposure is relatively fixed, non-compliance with the requirements of local linearization can be adjusted through the film.

14, what is the image resolution? Why emphasize it?

A: The resolution of the printed image on the printed base section has been introduced, we know that high-resolution images of the same size than the low-resolution images contain more pixels, the image information is also more performance details more clearly, which is consider the output image resolution factors to determine a reason. Because use of the image varies, it should use to determine the resolution of the image. If used as an image displayed on the screen, the resolution is 72Dpi or 96Dpi can; if used for 600Dpi printer output, you need 150Dpi image resolution; To print, you need high-resolution before 300Dpi line. Image resolution should be set appropriately: If the resolution is too high, running slow, the amount of disk space, do not meet the high principles; if the resolution is too low, affecting the expression of image detail, does not meet the quality principle. Greater China Graphic Arts Network

15 Why do you need an image with an image file format? Prepress often involves several image file formats, each with what nature?

A: The image file format should determine what type of information is stored in files, documents how the software is compatible with a variety of applications, files, how to exchange data with other files. Because there are a lot of image formats, the decision should be based on the use of images should be saved as an image what format.

Designs commonly used image file formats are:

TIFF format: TIFF image files are tagged to save the image composed by the color channel, and its biggest advantage is the image without platform restrictions, whether a PC, MAC or UNIX machine machine can be generic. It can save the Alpha channel, can be stored in a file separations data.

EPS format: EPS format is used for printing and printing, you can save Duotone information can be stored Alpha channel, you can store the path and screen information.

GIF is an 8 bit format, only 256 colors expression. Is a commonly used network communication image formats.

PSD is mainly used as an intermediate image file to save the image of the channel and layers, etc., to prepare for later modification. The format of continuity worse, only Photoshop can use it, there are few other applications that support it.

JPE is both a file format is a compression method, this compression is lossy, loss of varying sizes, some as small as the human eye can not tell.

16, what is the printed image screen lines? It is the image resolution, scan resolution, laser imagesetter output resolution is what kind of relationship between?

A: Because the print is composed by the network, so the printed image screen line number is printed in horizontal or vertical direction, the number of lines per inch, that is linked to the number of network cable. Called network lines because of the earliest printed outlets are linear. Hanged line unit is the Line / Inch (lines / inch), referred to as LPI. For example 150Lpi refers plus a 150-per-inch cable. To the image plus network, the greater the number of hanging mesh, mesh few more outlets more intensive level of expression more abundant.

Because the computer image is a lattice for bedroom and all of the pixels (the smallest unit of an image called pixels) composition. Image resolution can be understood as the image of the horizontal or vertical direction, the unit length of a line described by the number of pixels to describe this line is used by more pixels, the resolution will be higher. Of the resolution of the image is generally Pixels

PerInch (pixels / inch), usually expressed in English as PPI. For example, a resolution of the images is 300PPI, it means it is in the horizontal or vertical direction, there are 300 pixels per inch; an image resolution of 720I, it means it is in the horizontal or vertical direction, there are 72 pixels per inch.

Some devices have a similar resolution and image resolution, but they are expressed in a point, which is expressed as the Dot Per

Inch, referred DPI. If an image resolution of 1200DPI scanner image input accuracy can be collected for every inch 1200 points, or pixels. 3600DPI laser imagesetter graphic output accuracy of exposure 3600 per inch laser spot.

Image Resolution PPI and printing resolution LPI (screen lines) that is linked to another distinction: the image resolution is higher than the printing resolution, usually more than 2 × 2 pixels to generate a network, that is the DPI LPI half or so.

17, What kind of scanner?

Answer: ① drum scanner: sub-grade drum scanner and small desktop drum scanner.

② flatbed scanner: high, medium and low grades, should be used as a print design high, mid-range scanners.

③ handheld scanners for office.

④ transparent dielectric film and a scanner. For digitizing 35mm positives and negatives. Greater China Graphic Arts Network

18, the common output devices have? What are the respective field of application?

A: good page design electronic document may be the device output:

1. Monochrome Laser Printers: proofreading for printing black and white black and white formal draft or final.

2. Color Laser Printer: artwork for printing color effects formal draft or final color.

3. Color inkjet printer: artwork for printing color effects.

4. Large color inkjet printers: color effects for printing large formal draft or final color.

5. Digital proofer: for checking the content of the page, the color effect.

6. Laser imagesetter: copy used for the output Films.

7. CTP machine: for output printing plates.

8. Digital printing: printing directly from the electronic page output. Without the need for film and printing plates.

19, which has several types of scanners? What is the difference?

A: The scanner has two categories: one is the drum scanner; One is the flatbed scanner can be divided into high-end professional scanners, middle and low flatbed scanner. Drum scanner is evolved by the electronic color scanner, and its sensing technologies are photomultiplier tubes, Figure 5-1 is a drum scanner working schematic. The flatbed scanner is scanned by the CCD device to complete the work. Its working principle is different, the decision of two scanner performance difference:

(1) High-density coverage is different: drum scanner highest density of up to 4.0, and the average middle and low flatbed scanner is only about 3.0. Thus drum scanner in a dark place to be swept out of tune for more details, and to improve the image contrast.

(2) different image resolution: drum scanner with four photomultiplier tubes: three for color separations (red, green, and blue) and one for the virtual optical mask. It can make the object becomes unclear clearer, to improve image sharpness, the CCD is not the function of this main surface.

(3) different levels of image detail: a photomultiplier output after printing a scanned image, the details clear, dot delicate, textured small, while the flatbed scanner scans photo quality aspects of the fineness of the image is relatively worse more.

20, what is the Pantone color? Why use Pantone color to set the color?

Answer: Pantone ink is a famous American brand, has become a standard for color printing. It is his own production of all inks are made of Chromatography, color, Pantone's color color communication thus become recognized as a language, you need a certain color, just press color calibration on the line. Since the subject of extensive use of Pantone colors, computer design software has Pantone color libraries, and use it for color definition. When using Pantone color libraries set the color, choose Pantone colors can be defined method, but should be noted that most of the Pantone colors are spot colors, if the use of four-color reproduction, should be set as the primary color type. Figure 1-13 is an interface defined in Pantone colors.

21, what is the separation? Separation is it so important to you? How separations in Photoshop?

A: Separation is a printing professional terms, refers to the various colors on the original decomposition of yellow, magenta, cyan, black four primary colors; computer design or graphic design printed image class software, color separation work is to scan images or other sources of image's color mode to CMYK mode.

Generally scanned image to RGB mode, images captured with a digital camera for RGB mode, download pictures from the Internet are mostly RGB color mode. If the words to be printed, must be separation, into yellow, magenta, cyan, black four colors, which is the printing requirements. If the image color mode to RGB or Lab, output is likely to have only a K version outlets, namely RIP explain only the color information of the image is interpreted as gray.

In Photoshop, color separation operation is actually very simple: just put the image color mode from RGB mode or Lab mode can be converted to CMYK mode. Specific operation is performed Image / Mode / CMYK. So that the image color is the toner (ink) to represent, and having four color channels. When the film will be in the output image by color channel data generation outlets, and divided into yellow, magenta, cyan, black four separated film.

22, in separations, when the image from RGB to CMYK, the naked eye can see some colors on the screen will produce significant changes, which is why? What is the impact on the image color?

A: In the image from the RGB color mode to CMYK color mode, some of the images on some of the bright colors will produce significant changes, which sometimes can be clearly observed, usually by the bright colors become relatively dim Some colors. This is because the RGB color gamut than the CMYK color gamut in bigger, that some of the RGB color mode can be represented in some color to CMYK, the CMYK is beyond the range of colors to express, these colors can with similar color instead. Thus these colors produce a more significant changes. In fact, the image in the RGB color mode if there is color gamut beyond words, can Gamut Warning (Gamut Warning) preview.

23, what is the color space? Color space to figure out what is the significance?

In RGB, CMYK and Lab edit images, which are essentially different in different working color space. Gamut color mode refers to a table that can be expressed in the number of colors to Range area, also refers to specific media such as screen display, printer output and printing performance range of colors that can be replicated. Natural colors of the visible spectrum in the maximum color space, the color space which includes the human eye can see all the colors. In color mode, Lab color space maximum, which includes RGB, CMYK in all colors.

24, designed with the image's color mode in what mode is better?

A: In Photoshop, the image's color mode has RGB mode, CMYK mode, GrayScale mode as well as other color mode. Image mode used for the design of any model depends on what the end use of the design images. If the design of the image to be printed on paper or printed in the printing, the best color with CMYK color mode, so that the colors seen on the screen and printed colors or printed output close to the color. If the design is used in electronic media display (such as web pages, computer projection, video, etc.), the image's color mode is best to use RGB mode, RGB mode because the colors more vivid, richer, the picture look better. And the image of only three channels, the amount of data smaller, less disk space occupied. If the image is gray, then use GrayScale mode is better, because even with the RGB or CMYK color mode expression image still looks neutral gray color, but its disk space is much larger. Another gray image if you want to print, then, as expressed in CMYK mode, a film and printing when 4 version, costly not that also may cause printing gray balance control bad color cast problem when there is one color printing Excessive ink, makes a color cast gray images.

25, gold, silver is how to print? What are the requirements prepress design?

A: In the design, the customer often requires use gold and silver printing, as gold and silver can not be printed by the four-color color to achieve, so the printing and technology have special requirements. Printing, gold and silver are handled by spot colors, namely silver with gold ink and ink to print, so the film should also be a spot color film, a separate piece of a film, and a single copy printing.

In computer design should define a color to represent the gold and silver, and define its color type as a spot color can meet the design requirements. Since gold and silver is opaque, so the design can be gold, silver content is set to imprint (Overpint).

26, what is the spot color and spot color printing?

A: spot color printing means, not through the print C, M, Y, K 4-color composite of this color, but specifically with a particular ink to print the color. Spot color inks are premixed or by the printing ink factory production. For each one spot color printing, has specialized in printing a color version corresponds. Using spot colors make the color more accurately. Although the computer can not accurately represent the color, but color matching system through the standard pre-printed color swatch card, you can see the color on the paper accurate colors, such as Pantone color matching system created a very detailed color swatch card .

For the design of non-standard spot color set color printing is not necessarily accurate deployment out, but can not see on the screen, accurate color, so if it is a special needs do not easily use their own definitions of spot colors.

27, computer tables used method of color play what? General definition of color in what way is better?

A: Whether it is on a computer or in print, they need a way to describe different colors. Color color science on the table method, also known as color model or color mode. Table color color model many types, each of which can describe the color from different angles, but different color modes for different occasions, and the accuracy is different.

Computer table color mode has

1, RGB mode: also known as the RGB color space. It is a shade table color model, which is widely used in our daily life, such as televisions, computer display, slides, etc. are using light to blush. Often need to scan the image printing and publishing, scanner while scanning the first original image is extracted on the RGB spectrum information. RGB additive color mode is a mode via the R, G, B the amount of radiation can be described as a color. Computer defined color R, G, B three components ranging 0-255,0 that there is no amount of stimulation, the maximum capacity of 255 stimuli. R, G, B are 255, the synthesis of white, R, G, B are 0, the black is formed. On the display color definition, often using this model. Images, such as for television, slides, networking, multimedia, generally use the RGB mode.

2. CMYK mode: also known as CMYK color space. Personnel engaged in the printing industry who, CMYK is the most familiar. This model is a subtractive color model, follow the subtractive mixing rule. Real mode refers to a CMYK color reproduction print C, M, Y, K dot size, so C, M, Y, K value range is 0% to 100%. CO% MO% YO% KO% for white, C100% M100% Y100% K100% represents black.

3, HSB modes: Hue (HUE), Saturation (Saturation), Brightness (Brightness) mode.

28, since the RGB figure shows better than CMYK, the color is more beautiful, can not be directly output RGB chart? Doing what will happen?

A: Because the RGB color gamut than CMYK large, so some colors displayed on the screen was out, but the four-color ink was printed as expected to, in order to know the consequences, just try it. RIP is different, RGB color separation film that might figure in the black version has only a chart, other color versions no map, there may be four-color film photo information (outlets) are identical, that is the equivalent grayscale , although some can Fapai software or RIP converts RGB CMYK, but preferably using the scanning software or Photoshop for mode conversion.

29, will be saved as DCS format color print black and white artwork is a map, but the output is not on the film map. Why is this?

A: The picture is stored as part of DCS format will produce five documents,

30, what is the RIP? Why now prefer to use the software RIP?

A: RIP is RasterProcessing acronym refers typesetting system will be interpreted as a bitmap PostScript encoding software or hardware cards, commonly known as raster image processor. It is in the color publishing system plays an important role, its function is to make a good page quickly interpreted as the recorder output can be controlled laser dot commands, it will be a page of text, graphics, images and other elements are automatically converted into digital lattice information, then the information recording control output devices, let job is "OFF" or "ON."

RIP hardware replacement requires complex technology and a long time, unable to adapt to the rapid development of software technology; while its RIP software update soon, handling of high quality, high speed, the result can be displayed after treatment, etc. are widely used. And a software RIP can simultaneously drive multiple imagesetter, strong networking capabilities.

31, the layout and graphics software category Why not set the resolution?

A: typesetting graphics software is object-oriented software, text, graphics representation are used to express the algorithmic language, an object produced is resolution-independent, which is based on the output when the output resolution of the output device , the output device resolution is high, making the page graphic output resolution is high. Therefore, graphics software and desktop publishing software like without setting resolution. Layout and graphics software to import images in the output will have to read the original lattice information, which related to the resolution of the original image.

32, CorelDraw Chinese There are several types of this?