How Designers Check Film

First, the importance of film

Film plays a role in the printing and is an indispensable part of printing. We all know that the printing process is: manuscript → plate leaf output film → proofing → printing → post processing → finished product. Although the digital direct-to-plate technology CTP is developing very rapidly, it will take a while to popularize applications. The film in the traditional printing process is still one of the key links of printing. Without film, it cannot be printed and cannot be printed.

Second, check the purpose of the film

The film quality influencing factors include the perfection level of the software rip, the working experience of the production staff, and the working experience of the distribution personnel. The degree of understanding of the use of the software by the production staff and the release personnel determines whether the output film can be normally printed on the machine. The error rate is very high, so checking the film is necessary for each printing company and prepress company. The purpose of checking the film is to eliminate various unfavorable factors in the printing process or to avoid some printing process errors that may occur.

Third, check the tools of the film

Magnifier, scale, standard chromatogram, oil pen, densitometer, dot angle ruler

Fourth, check the film steps

1. After obtaining the film, it is firstly confirmed whether the number of films is consistent with the requirements for use. Generally, the film includes a monochrome film, a four-color film, a spot-color film, and a film with a positive back cover.

2. Under the premise of determining the appropriate number of films. Check the film fit. In general, one sheet with a large area of ​​color is used as a reference on the platen, and the other three sheets of film are fitted. Under the normal thickness of the fitting line, no more than half line error is allowed. Text, lines, and image edges cannot be ghosted.

3. Next divide each film color. Some films have a color standard CMYK, so don't talk about it. Some films do not have a color mark, which can be identified by contrasting the color blocks of the film against the characteristic color blocks on the color manuscript and marked with an oil-based pen. If the film in question needs to be reissued, it should be noted that the first time and the second time should be marked separately.

4. Check the film size. According to the worksheet, check if the film size is the same as the requirement. When outputting the film, add all the centerline, sleeveline and cutting line. If there are proofs, do a good job of proofs of the finished product. If there are no proofs, check the dimensions as required by the size of the finished product. One item per item must be checked. If it is a bag, envelope or kit, and other informal size requirements, but also carefully check whether the sticky mouth, folded mouth, bottom of the box, bleeding, leaving enough white edge and so on. Finally, check whether the film size plus the size of the mouthpiece can be printed normally. (Large-version version adds 13mm to both sides, and if the paper does not allow, it must be printed in two versions).

5. Checking the imposition method is also very important. Imposition methods are generally self-reviewed, large-version version and large version. What kind of layout to fight depends on the specific circumstances, since the version and large version should be symmetrical with the middle line, it is very important to check whether the distance from the center line to both sides is equal. The imposition direction should be relatively symmetric, and the error of the large set of positive back sets should be within 1 J, and the corresponding lines can all be matched. Also note that some work staples that require posterior binding or folding must be correctly folded.

6. The layout and text content should also be checked after the imposition is correct. Check whether the customer's place of change is correct, and then check whether the layout and content of the customer are consistent with the manuscript. Properly proofread and proofread the wrong mistake. The position of the mosaic must be accurate and the content can be connected.

7. If there is only plastic cloth with no proof on the color spray, it is necessary to check whether the color of each color version of the four-color film is consistent with the color of the color draft, and the color on the color draft should correspond to the corresponding film.

8. If it is reissued or modified, the new film and the old film are checked one by one. The changed areas have been changed or the density or the number of outlets has changed, and the new and old films are marked with oily pens.

9. Carefully check the color screens, transitional networks, and whether the scratches, dirty spots, ghost spots, laser lines, creases, and noise points on the picture are smooth.

10. Experience If you can not determine the density of the film can meet the printing needs, use the density meter to detect the film, according to the film platooned 3.4 or more, the electrical fragmentation 3.8 or more.

11. If there are no traces of profiling on the proofing or proofing, the angle of the screen should be checked. Under normal circumstances, the screen angle is 0°, 15°, 45°, and 75°. If there is a uniform angle between the two color versions of the network cable, a moire must occur and the cable angle must be changed.

12. If you feel that the film network cable is rough or the proofing network is large, you should check whether the number of hairline cables meets the needs of the job. Offset printing is generally 130l, newsprint is generally 100l, coated paper is generally 175l, and high-grade printing is generally 200l.

13. After the entire film is inspected, it is best to use some eye-catching pens to draw out changes in some places. Explicitly indicate where to change. If you can't change it by hand, please reissue the film. Otherwise, it takes a long time to associate with the sun, the printing plate is difficult, it is easy to make mistakes, and the customer's requirements are high. It may not be possible.

14. The extra corner lines within the finished line must be removed.

15. Some of the above checks may have been avoided in the production process, some may not be used, and are too cumbersome. I hope to use my own knowledge and experience in the inspection to select uncertain and unsure ones, saving inspection time and improving effectiveness.

16. In general, customers are required to proof. After proofing, many problems can be found and many problems can be solved. In combination with the film, it can basically guarantee normal printing on the machine. The inspection of film flat screens is particularly important. Attention should be given to them. If something is inappropriate, the problems reflected in printed matter are uneven or dizzy.