Detailed explanation of the hottest film output pr

Detailed explanation of film output process

in order to faithfully reproduce your creativity on paper without harmful materials such as benzene and formaldehyde, in addition to exquisite design, it is more critical to have standard and error free output as a guarantee. Therefore, it is very important for computer designers to understand the importance of output. Photoshop is the most widely used image processing software at present. To have a good output effect, the premise is to find the best manuscript; Use the best roller scanner; The DPI is set to twice the printing line. Before making a four-color manuscript, the graphics must be converted to the interface design of the CMYK mold testing machine. If it exceeds 10 megabytes, it needs to be stored in EPS format and color separation. Compression or other formats are not used. After the picture is finished and does not need to be modified, the unused channels must be removed. If there are multiple layers, you must merge all the useful layers and remove the unused layers before saving. After the edition is arranged, if the picture is modified or renamed, the picture must be repositioned or connected. Freehand is a widely used typesetting software at present. In order to obtain a good gradient effect, you should set a high resolution in the page before making it. In addition, it is recommended to use Photoshop or illustrator for gradient. Please use less fill and srtouch, pattern fill in the blank effect, so as not to affect the quality of output. CorelDRAW is the most used typesetting software on PC. If you want to get the best film or proofing in the shortest time, please don't use RGB color to fill color blocks or lines in the production process; After turning into a curve, the number of nodes of the text shall be controlled within 1500 points; Use PSD format as little as possible for graphic files; Spot color can be Pantone special color, not Pantone printing color

1. Skip word

there are two main reasons for skipping word during output: one is that the position of the word is not adjusted after changing the font, and the other is that there are spaces between words. For the former case, the only way is to readjust the position of the word after changing the font, while for the latter case, there are two solutions: first, divide the word into two parts and arrange it according to the original position; Another solution is to use TrueType font. After determining the position of the word and the figure, outline the word. However, it should be noted that the space between the words must be English space, otherwise after the outline, the empty position will appear "mouth"

2. Transparent black-and-white map

there is a problem when saving the map as a tiff map in grayscale mode in Photoshop and putting it into freehand -- when selecting black overprint, if there are color blocks or other basemaps under the grayscale map, its white part will become the corresponding part of the color block or basemap. The reason for this problem is that the default color filling of the grayscale map put into Photoshop by freehand is k100. When selecting black overprint, The white part is considered as CMYK is zero, which naturally shows the color of its color version. For this situation, there are two solutions: first, in Photoshop, turn gray into CMYK, in the CMYK total channel of the channel dialog box, selec all, copy to channel black, and then delete the images in C, m, and Y channels; Another solution is to change the coloring of grayscale map to Y1 and k100 in freehand, so that there will be no problem when selecting black overprint

3. Color

the color of the display has a certain impact on people's feeling of the picture, so it is necessary to use gamma software to adjust the screen to be close to proofing, so as to be closer to the color itself when the photo shop colors the picture in the future. It is better to adjust the screen color directly by the users who often use this machine, and do not rely on the sales manufacturers and other replacements, because each user's color sense is different. In freehand and other typesetting software, set the color to the printing color system. If you want to use a special color, you can choose Pantone color system, or set the color to spot type, that is, a specific color. When using a special color, it is best to store the image in bitmap format, because bitmap is not transparent. In typesetting, if you need to manually make cutting lines and alignment lines, you must set a four-color black color, namely C100, M100, Y100, k100, so that each color separation plate has it. At the same time, these lines must be set as hairline, namely the thinnest line, to improve the accuracy of version alignment. If there is another spot color on the above cutting line, these spot color lines must be made in situ at the same time. Freehand and other typesetting software have some differences between the set color on the screen and the actual situation. Therefore, it is usually possible to use the printing color code as a reference, and then set the hue, and use freehand to publish newspaper manuscripts. If it is a two-color overprint plate, but there are EPS pictures including monochrome black, at this time, the figure cannot be saved in grayscale mode, otherwise the figure will be divided into four colors when output. Because only two versions are issued, the hue of the figure will be low. For this reason, You must save the image in CMYK mode, copy the contents of the whole page to version K, and then delete the contents of CMY respectively, so as to ensure the correct output

4. Output light film

(negative film) there are generally three situations for output light film (negative film),

(1) it is required to enlarge the advertising light box

(2) when converting RGB to CMYK in computer production, if a certain color distortion is found, the RGB output lamp must be separately divided

(3) when the customer's lamp is accidentally damaged. Production requirements:

(1) computer files must be RGB

(2) channels and paths must be merged

(3) save in TIFF format

(4) make according to the proportion of lamp specifications, such as 4 "*5" 135 (240*320), not necessarily according to the actual production of lamp,

(5) the unit of measurement of lamp production is 2K, 4K, 8K 16K, 2K, that is, 1024*2=2048 pixels (pixels), 4K 1024*4=4096 pixels, and the rest of the units are pushed like this, for example: 4K 4 "*5" lamp contains 4096 pixels within the range of 5 ", which can also be expressed as 4096 pixels/5" =800 DPI picture scanning with high general elements, The 4 "*5" light film output into 4K can also cope with the printing of split posters, 2K 135 can be amplified by 8*10 "

5. The image mode noted during output

bitmap -- bitmap. Photoshop bitmap mode is a black-and-white image, and each pixel of the black-and-white image is represented by 1-bit data, that is, the pixel of the display image is either black or white, so the image occupies the smallest storage space. But windows BMP is also a bitmap, but it occupies a huge space. Grayscale -- gray scale, in the gray scale mode, every pixel of the image A pixel is represented by 8 bits, and each pixel is represented by 256 gray levels (gray levels) between black and white. Gray image has no color. When a color image is converted into gray, Photoshop will display a warning message of image information reduction, prompting users whether they really want to discard the color information. Indexed color -- indexed color. In the image with RGB, CMYK and lab modes, each pixel on the screen contains complete color information, but the image also occupies a large storage space. In the actual output, there are generally only dozens or hundreds of colors used in an image, so if the colors used are established into a color table, the color of each pixel on the screen is only a certain position in the color table, which can save the corresponding storage space of the image. Using this method to record or display the image is the index color mode. RGB color -- RGB mode is the main image display and processing mode of Photoshop. RGB mode uses red, blue, and green, so flexible packaging manufacturers do not need three basic components of colors to synthesize most of the colors they can see. CMYK color -- CMYK mode is composed of four basic colors: cyan, magenta, yellow and black. Various colors are generally used in the field of color separation processing of printing output. Lab color -- the lab mode represents the color with a luminance component L (lightness) and two components a and B, in which a component green evolves to red, while blue evolves to yellow

6. Lithography principle

there are several printing methods in printing, such as lithography, relief printing, intaglio printing, etc. at present, relief printing is used in books, newspapers and packaging printing in China, while relief printing has been replaced by lithography in foreign countries. Compared with relief printing and gravure printing, lithographic printing process has its own uniqueness, which can be summarized as follows:

1) The practical application of the natural law of immiscibility of oil and water in lithography. Lithography uses the law of immiscibility of water and oil to achieve the purpose of printing. At present, lithography is still inseparable from water

2) For a lithographic printing plate, the blank part and the graphic part are almost on the same plane of the printing plate. Using the law that water and oil are immiscible with each other, through technical treatment, the lipophilic and hydrophobic graphic part and the hydrophilic and hydrophobic blank part are formed on the same plane of the printing plate. In the printing process, the wetting mechanism first applies a uniform amount of water to the blank part of the printing plate, which does not adsorb ink, and then the inking mechanism adsorbs an appropriate amount of ink to the graphic part, which completes the transfer and reproduction of the graphic through the imprinting mechanism, so as to achieve the purpose of printing

3). The way of lithography is an indirect printing. The graphics on the printing plate are "regular". The ink on the lithography plate is not directly transferred to the paper, but first transferred to the rubber drum, and then transferred to the printing material. Therefore, its graphics and texts are "regular", which belongs to indirect printing. The rubber blanket wrapped on the surface of the rubber drum has two characteristics: first, it has good hydrophobic and lipophilic characteristics, which can fully transfer ink and limit the transmission of water; second, the rubber blanket is elastic, and it can print solid impressions with small expansion rate under large printing pressure and compression deformation

4). Dot matching -- the colors presented by lithographic products are ever-changing and beautiful. The formation of their colors is formed by overlapping dots and color ink, and dot matching is the main. It is guided by the light color theory, using the means of dot overlapping and juxtaposition, and sometimes adopting cast structure, cast steel, cast aluminum, etc. 3 The requirements for fixture structure are based on the theory of three primary colors or three primary colors plus black (four colors), through photographic color separation or electronic color separation, the color of the picture is decomposed into four color plates with different grain angles, such as yellow, magenta, cyan and black, and then the four-color printing plate and overprint overlap to reproduce countless levels and colors, so as to obtain artistic copies with very rich colors

5). Multicolor overprint, printing a wide range of formats -- lithography can print monochrome text, but mainly multicolor overprint. The printing format can be large or small (four open - double full sheet) and multi-color products with dots and fields can be printed at the same time. The finished products have flat pictures and bright colors, which are inferior to other printing methods. The graphic part and blank part of the lithographic plate are on the same plane, which have completely opposite properties to the affinity between water and oil. The graphic part is lipophilic and hydrophobic, while the blank part is hydrophilic and hydrophobic. The function of the graphic part is to absorb the ink and repel the fountain solution. In the printing process, the blank part is first wetted by the fountain solution, then the graphic part is coated with ink, and then the ink of the graphic part is transferred to the paper. Lithography is based on the principle of immiscibility of oil and water to transfer the pictures and texts on the printing plate to the paper. (to be continued)