Film plays an important role in printing and is an indispensable link in printing. We all know that the printing process is: manuscript → plate making → output film → proofing → printing → post-processing → finished product. Although digital direct plate-making technology CTP is developing very fast, it will take some time for popularization and application. Nowadays, the film in the traditional printing process is still one of the key links of printing. Without film, it is impossible to print and print.
Second, the purpose of checking the film
The earliest printed film was completed by photo-engraving. The human factors and technical level have a great influence on the quality of the film. Nowadays, the printed film is generally a phototype output machine that interprets the produced document through rip into digital image dot data , And then output the results of the arranged version to the film to complete. The factors influencing the quality of the film include the perfection degree of the software rip and the working experience of the production personnel, and the working experience of the development personnel. The degree of knowledge of the production staff and the layout personnel on the use of the software determines whether the output film can be printed on the machine normally, which has a very high error rate, so checking the film is a must for every printing company and pre-press company. The purpose of checking the film is to eliminate various disadvantages that occur during the printing process or to avoid some printing process errors that may occur.
3. Tools for checking film
Magnifying glass, scale, standard chromatogram, oil-based pen, density meter, dot angle ruler
Fourth, check the film steps
1. After getting the film, first confirm whether the number of films is consistent with the requirements for use. Generally, it includes single-color films, four-color films, spot color films, and enough film for the front cover.
2. Under the premise of determining the appropriate number of films. Check the film fit. Under normal circumstances, on the transparency table, one of the large-area colors is used as the reference to fit the other three films, and the error of more than half of the line under the normal thickness of the registration line is not allowed. Text, lines, and the edges of the image must not overlap.
3. Next, distinguish the color of each film. Some films have color-coded CMYK, so needless to say. Some films do not have color marks, you can use the color blocks on the film to compare with the characteristic color blocks on the color manuscript for identification, and mark them with an oil-based pen. If the problematic film needs to be reissued, it should be noted that the first and second time should also be marked separately.
4. Check the film size. Check whether the size of the film is the same as the requirements according to the work order. When outputting the film, you should add all the center line, sleeve line and cutting line. If there are proofs, make craft proofs according to the requirements of the finished product. If there are no proofs, check the size according to the size requirements of the finished product. Each relevant size must be checked one by one. If it is a non-regular size requirement such as a handbag, envelope or medicine box, it is necessary to carefully check whether there is a sticky mouth, a fold, the bottom of the box, bleeding, and whether the white border is left enough. Finally, check whether the size of the film plus the size of the bite can be printed normally (plus a bite of 13mm on each side of the large turnover version, if the paper does not allow, then two sets of plates should be printed).
5. Checking the imposition method is also very important. The imposition methods generally include self-reversion, large-reverse version and large-set version. The type of layout depends on the specific situation. The self-retroversion and the large set should be symmetrical with the center line. It is very important to check whether the distance between the center line and the two sides is equal. The direction of the imposition should be relatively symmetrical, the error of the front and back of the large set should be within 1l, and all the corresponding lines can be aligned. It should also be noted that some live folding hands that require back binding or folding must be correct.
6. After the layout is correct, you should also check the layout and text content. Check if the customer changes are correct, and then check if the layout and content are consistent with the original. Proofreading should be done carefully to prevent mistakes and corrections. The position of the mosaic must be accurate and the content can be docked.
7. If there is only color-printed 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-printed draft. The color on the color-printed draft should correspond to the corresponding film.
8. If it is a reissue or modified reissue, the new film and the old film should be checked one by one correspondingly. The changed place has been changed or there is no change in the color density or dot count. The new and old film should be marked with an oil pen.
9. Carefully check the flat screens and transition nets of various colors for scratches, dirty spots, virtual light spots, laser lines, creases, noises, and smooth transitions.
10. If you can't determine whether the density of the film can meet the printing needs with experience, use a density meter to detect the film, the photo film is more than 3.4, and the electric film is more than 3.8.
11. If there is no proof or there are no obvious traces of moire on the proof, the angle of the network cable should be checked. Generally, the angle of the network cable is 0 °, 15 °, 45 °, 75 °. If the two-color version of the network cable has the same angle, the moire must appear, and the angle of the network cable must be changed.
12. If you feel that the film network cable is rough or the proof dots are large, you should check whether the number of hairline cables meets the needs of live parts. Offset paper printing is generally 130l, newsprint is generally 100l, coated paper is generally 175l, high-end printing is generally 200l.
13. After the entire film inspection is completed, if there are some changes in the place, it is best to outline them with a striking pen, clearly indicating the place to change, if you can not change it by hand, it is best to reissue the film. Otherwise, it takes a long time to print together, it is difficult to print, it is easy to make mistakes, and customer requirements are high, which may not be possible.
14. Excess corners within the finished line must be removed.
15. Some of the above inspections may have been avoided during the production process, and some may not be used. It is too cumbersome. I hope to use my knowledge and experience to select uncertain and unsure items during the inspection to save inspection time. ,Improve efficiency.
16. In general, customers are required to make proofs. After the proofs come out, many problems can be found and solved. Combining the film can basically guarantee the normal printing on the machine. The inspection of the film flat screen is particularly important, and it should be paid attention to. If one point is not suitable, the problem reflected by the printed matter is unevenness or halo.
Plastic Ruler,Glue Stick,Liquid Glue,Paint Brush Set
NINGBO MACEY EDUCATION PRODUCT CO.,LTD , https://www.maceycreative.com