How to inspect film 0 when purchasing before the f

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How to inspect the film before printing? First, the importance of film. Film plays a connecting role in printing and is an indispensable link in printing. We all know that the printing process is: original → plate making → output film → proofing → printing → subsequent processing → finished products. Although the digital direct plate making technology CTP has developed very fast, it still needs some time to be popularized and applied. Now the film in the traditional printing process is still one of the key links of printing. Without film, you can't print and print

second, the purpose of checking film

the earliest printing film was completed by photographic plate making. Human factors and technical level have a great impact on the film quality. The operation of plastic granulator touches on a wide range of areas of the national economy. Now, printing film is generally completed by phototypesetting output machine, which interprets the produced documents into dot matrix data of digital images through rip, and then outputs the arranged version results to the film. The factors affecting film quality include the perfection of software rip, the working experience of production personnel, and the working experience of distribution and arrangement personnel. The level of understanding of the producers and arrangers about the use of the software determines whether the output film can be printed normally, and the error rate is very high, so every printing company and prepress company must check the film. The purpose of checking the film is to eliminate all kinds of adverse factors in the printing process or to avoid possible printing process errors

III. tools for checking film

magnifying glass, scale, standard chromatography, oily pen, densitometer, point angle ruler

IV. steps for checking film

1 After getting the film, first confirm whether the film quantity is consistent with the use requirements, generally including monochrome film, four-color film, spot color film, and whether the film on the front and back cover is enough

2. On the premise of determining the appropriate number of films. Check the film sleeve. In general, one of the films with a large area of color is used as the benchmark on the transparent stage to nest the other three films. Under the normal thickness of the nesting line, no more than half line error is allowed. Text, lines, and image edges cannot be overlapped

3. Next, distinguish the color of each film. Some films are colored with CMYK, so needless to say. Some films do not have color codes, so they can be identified by comparing the color blocks on the film with the characteristic color blocks on the color manuscript, and marked with an oily pen. For the films with problems that need to be rearranged, it should be noted that the first and second rearrangements should also be marked differently

4. Check the film size. Check whether the film size is the same as the requirements according to the work order. When outputting the film, all the center lines, nesting lines and cutting lines should be added. If there are samples, make process samples according to the requirements of finished products. If there is no sample, check the size according to the finished product size requirements. Each relevant dimension must be checked one by one. In case of irregular size requirements such as handbags, envelopes or medicine boxes, it is more necessary to carefully check whether there are sticky openings, folds, box bottom, bleeding, white edges, etc. Finally, check whether the film size plus the bite size can be printed normally (13mm bite is added on both sides of the large turn over version respectively. If the paper is not allowed, two sets of plates should be dried)

5. It is also important to check the typography. There are generally self copying, big turning and big copy making methods. What kind of layout to spell depends on the specific situation. Self reproduction and large format should be symmetrical with the center line. It is very important to check whether the distance from the center line to both sides is equal. The direction of the composition should be symmetrical, the error of the front and back cover of the large set should be within 1L, and all the corresponding lines can be aligned. Also note that some live parts that need to be bound or folded at the back must be folded correctly

6. After the composition is correct, you should also check the layout and text content. Check whether the changes made by the customer are correct, and then spot check whether the layout and content are consistent with the original. You should proofread carefully to prevent mistakes from being corrected again and again; The position of the mosaic map must be measured accurately, and the content can be connected

7. If there is only plastic cloth without proofing, check whether the color of each color version of the four-color film is consistent with the color separation of the color inkjet manuscript, and the color on the color inkjet manuscript should correspond to the corresponding film

8. In case of re layout or change of layout, the new film and the old film shall be used to check each color version one by one. If the changed place has been changed or the color density or dot ratio has changed, the old and new films shall be marked with an oily pen

9. Carefully check whether there are scratches, dirty spots, virtual light spots, laser lines, creases, miscellaneous spots, smooth transitions, etc. on the pictures

10. If experience cannot determine whether the density of the film can meet the printing needs, use a densitometer to detect the film, with phototypesetting film of more than 3.4 and electronic segmentation film of more than 3.8. Plastic seems to have become the core material of power cables and electronics

11 If there is no proofing or there is no obvious moire mark on the proofing, the line angle should be checked. First, the new material industry to which it belongs has high technology intensity, high research and development investment, high added value of products, and strong internationality of production and market. Generally, the line angle of 0 °, 15, or even mutually complementary status will exist for a long time °, 45 °, 75 °. If there are two colors on the line with the same line angle, moire must appear, and the line angle must be changed

12. If you feel that the film line is rough or the proofing point is large, you should check whether the number of hair lines meets the needs of live parts. Offset paper printing is generally 130L, paper is generally 100L, coated paper is generally 175L, and high-end printing is generally 200L

13. After the whole film is checked, if there are changes in some places, it is best to outline them with an eye-catching pen and clearly indicate the change place. If it cannot be changed manually, it is best to resend the film. Otherwise, it takes a long time to print, which is difficult to print, easy to make mistakes, and the customer's requirements are high, which may not be possible

14. Excess corner lines within the finished line must be removed

15. Some of the above inspections may have been avoided in the production process, and some may not be used, which is too cumbersome. I hope to use my knowledge and experience to select uncertain and uncertain items in the inspection, so as to save inspection time and improve efficiency

16. In general, customers are required to proofing. After proofing, many problems can be found and solved. Combined with the film, it can basically ensure the normal printing on the machine. The inspection of film flatness is particularly important, which should be paid attention to. If there is a little unsuitable, the problem reflected by the printed matter is uneven or dizzy

source: printer

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