Printing output considerations

How to faithfully reproduce your ideas on paper, in addition to exquisite designs, it is even more critical to have a standard and unmistakable output as a guarantee, so it is important for computer designers to understand the importance of output. . PhotoShop is currently the most widely used image processing software. If you want to have a good output, the premise is to find the best manuscript; use the best roller scanner; DPI is set to 2 times the printing cable, before making four-color manuscripts , The graphics must be converted to CMYK mode. If it exceeds 10 MB, the format of the EPS must be used and the color must be stored. Do not use compression or other formats. After editing the picture, you need not modify the channel. Remove it. If there are multiple Layers, all the useful Layers must be merged, and the unused Layers can be saved. After the layout is finished, if the picture has been modified or renamed, the picture must be relocated or connected. Freehand is currently the most widely used typesetting software. To achieve a good gradient effect, you must set a high resolution on the page prior to production. It is also recommended to use PhotoShop or Illustrator for gradients. Please use Fill and srtoke less to fill in the blank, so as not to affect the quality of the output. CorelDraw is the most typesetting software used by users on PCs. To get the best film or proof in the shortest possible time, please don't use RGB color to fill the color blocks or lines in the production process. The number of nodes in the text should be controlled within 1500 points. Minimal use of PSD format for graphics files; Pantone special colors available for spot colors; Pantone printing colors are not available.

Output trapping skipping words - There are two main reasons why skipping occurs in the output: one is that the font is not repositioned after the font is replaced, and the other is that there is a space between the words. The only way for the former case is to re-adjust the position of the word after the font is changed, and there are two ways to solve the latter: first, divide the word into two parts and place it in its original position; The solution is to use True Type fonts, the word and map position determined, the word Outline, but it should be noted that the spaces between the words must be English spaces, otherwise after the Outline, the empty position will appear " mouth".

The bottom black-and-white map saves the map as a TIFF map in Grayscale mode in PhotoShop. Placing it in Freehand uses a problem - if a grayscale graph is underneath a colored block or other basemap when choosing a black overprint, the white part of it will The reason for this problem is that the Grayscale plots that Freehand put into PhotoShop are filled with K100 by default. When black overlays are selected, the white part is considered to be zero for CMYK. This naturally occurs. It reveals the color of its color version. For this case, there are two ways to solve: First, in the PhotoShop, the Grayscle into CMYK, in the Channel dialog CMYK total Channel selec all copied to the Channel Black, and then delete the C, M, Y three The image in the Channel; another way is to change the fill color of the Grayscale graph to Y1, K100 in Freehand, so that there will be no problem when selecting the black overprint.

The colors of the color display make people feel that the picture has a certain influence, so the Gamma software must be used to adjust the screen so as to approach the proofing, so that when coloring the picture in PhotoShop later, it is closer to the color itself. Adjusting the color of the screen is best done directly by users who frequently use this machine. Do not rely on vendors and other replacements because the color perception of each user is different. In Freehand and other typesetting software, set the color to print color. If you want to use a dedicated color, you can use the Panton color system, or set the color to the Spot type, which is a specific color. When a graph uses a dedicated color, the graph is best stored in the BitMap format because BitMap is not transparent. In the typesetting, if you need to manually cut the first use of the alignment line, you must set a four-color black color, namely C100, M100, Y100, K100, in order to have each color version, and these lines must be set For Hairline, the finest line, to increase the accuracy of the version. Above the cut line, if there is another spot color, these spot color lines must be made in-situ. Freehand and other typesetting software, in the set of colors on the screen and the actual difference, so you can usually borrow the printing color for reference, and then set the hue, with freehand out of the newspaper, if it is a two-color printing plate, but there are Including monochrome black EPS images, the graph can not be saved as Grayscale mode, otherwise the output will be divided into four colors. Since there are only two versions, the hue of the graph will become lower. Therefore, Save the map as CMYK mode, and copy the entire version to the K version. Then delete the contents of the CMY version separately to ensure that the output is correct.

The output lamp (negative) requires output lamp (negative) There are generally three situations:
(1) Request to enlarge the advertising light box;
(2) When the computer production was changed from RGB to CMYK, a certain color was found to be distorted, and the RGB output lamp should be separately divided;
(3) When the customer's lamp is accidentally damaged.
Production requirements:
(1) The computer file must be RGB;
(2) Consolidation of Channels and Paths;
(3) Save as TIFF format;
(4) Produced according to the proportion of lamp specifications, such as 4 "*5" 135 (240 * 320), etc., not according to the actual production of the lamp (5) The measuring unit for the production of the lamp is 2K, 4K, 8K, 16K , 2K is 1024 * 2 = 2048pixel (pixels), 4K 1024 * 4 = 4096 pixel the rest of the units and so on, for example: 4K 4 "* 5" lamp, in the 5 "range contains 4096 pixels, can also Expressed as 4096 pixel/5”=800 dpi high-level image scan, output 4K 4”*5” lights, also able to cope with the printing of posters, 2K 135 can be enlarged 8 “*10” Photo to do.
Bitmap - Bitmap - Bitmap - Bitmap - The Bitmap bitmap is a black and white image. Each pixel of a black and white image is represented by a single bit of data. That is, the pixels of the display image are either black or white. Images also have the smallest amount of storage space. However, WINDOWS BMP is also a bitmap, but it takes up a lot of space. Grayscale - Grayscale. In grayscale mode, each pixel of the image is represented by 8 bits representing 256 gray scale representations (gray scales) between each black and white pixel. Grayscale images have no color. When converting a color image to grayscale, PhotoShop will display a warning message with reduced image information, prompting the user whether or not to actually abandon the color information. Indexed Color - The index color, the image using RGB, CMYK and Lab mode, each pixel on the screen contains complete color information, but the image takes up more storage space. In the actual output, the colors used by an image are generally only tens or hundreds, so if the colors to be used create a color table, the color of each pixel on the screen is only one of the colors in the color table. Position, you can save the image of the corresponding storage space, use this method to record or display the image that is the index color mode. RGB Color - RGB mode is the main image display and processing mode of PhotoShop. The RGB mode synthesizes most of the visible colors using the basic components of red (RED), blue (BLUE) and green (GREEN) colors. CMYK Color - The CMYK color is composed of four basic colors: CYAN, MAGENTA, YELLOW, and BLACK. These colors are generally used in the color separation processing of printed output. Lab Color - Lab Confiscation is based on a luminance component L (lightness) and two components a, b, where the a component green color evolves to red, and the component blue to yellow.

The lithographic printing principle is divided into several types of printing methods: offset printing, letterpress printing, gravure printing, etc. China's books, newspapers, and packaging prints currently use letterpress printing, while foreign letterpress printing has been replaced by lithographic printing. Compared with letterpress printing and gravure printing, lithographic printing technology has its unique features and is summarized as follows:
(1) The practical application of the natural law of immiscibility of oil and water in lithography. Lithography uses the laws of water and oil incompatibility to achieve the purpose of printing. At present, lithography is also inseparable from water.
(2) For lithographic printing plates, the blank and graphic parts of the printing plate utilize the laws of water and oil incompatibility on the same plane of the printing plate. The graphic part and the blank part of the hydrophilic oleophobic. In the printing process, the wetting mechanism first applies a uniform amount of water to the blank portion of the printing plate, and the blank portion does not absorb the ink, and then the ink is used to make the graphic portion absorb an appropriate amount of ink, and the graphic is completed by the embossing mechanism. Transfer the copy to achieve the purpose of printing.
(3) The lithographic printing method is an indirect printing. The pattern on the printing plate is “positively shaped”. The ink on the lithographic printing plate is not directly transmitted to the paper but is first transferred to the blanket cylinder. The ink is then transferred to the printing material, so the graphic is "in the right shape" of indirect printing. The rubber blanket wrapped on the surface of the blanket has two characteristics: First, it has better hydrophobic and oleophilic characteristics, it can fully transfer ink, and restrict the transmission of moisture. Second, the blanket has elasticity and can be larger. In the case of printing pressure and compressive deformation, the imprint of the solid surface enlargement rate is small.
(4) Dot fineness - The color of the flat-printing products is ever-changing and beautiful. The formation of color is made up of dots and color inks, and the fineness of the dots is the main one. It is guided by the light color theory. The overlapping, parallel means of the dots are based on the theory that the three primary colors or the three primary colors plus black (four colors), through the photo separation or electronic color separation, decompose the color of the picture into yellow, magenta, cyan, black, etc. with different reticulation angles. Color version, and then use four-color printing plate, overprinting overlap to reproduce numerous levels and colors, to obtain very colorful art replicas.
(5) Multi-color overprinting, wide range of printing format - lithographic printing can print monochrome text version, but mainly multi-color overprint. The printing format can be large or small (four-on-two-sheets) and can also be printed with multi-colored products on the screen and on the field. The finished product is flat and colorful, which is not comparable to other printing methods. The graphic part and the blank part of the lithographic printing plate are on the same plane. The two parts have completely opposite properties for the water and oil intimacy. The graphic part is oleophilic and hydrophobic, while the blank part is hydrophilic and oleophobic. The role of the graphic part is to adsorb the ink to reject the fountain solution. During the printing process, the blank part is first moistened by the fountain solution, and then the graphic part is coated by the ink, and then the graphic part of the ink is transferred to the paper. Lithography is based on the principle of immiscibility between oil and water, transferring the graphic on the plate to the paper.

Source: PACK.CN