Master Luo, who has been in business for more than 20 years, has accumulated rich operational experience in printing and has a "coupling coup" for many printing problems. Some small partners specially leave a message, hoping to learn more about printing technology from Master Luo's practical experience. Therefore, Xiao Bian specially sorts out the experience summarized by Master Luo and gives you a real technical feast.
Printed black
In the printing process, the easiest thing we can touch is to print black. How can we print black? Pay attention to the following points.
1. The printed black color is not even black if it is k100. It is because of the printing machine rubber - equipment, which is a common problem. So if it is monochrome (special color) printing, you can print it twice, but if there is a shallow net in pure black, it will be 50%-70% on the original basis. For example, if the shallow net is k60, then if it is printed twice To adjust to k35 or so, it is best to have a standard proof for the printing master to adjust.
2, the black color of the four-color machine printing, must be added c30 in the design, but simply add a color to see the blue light from the side, for the food industry, there is something wrong. Our experience: c60m60y40k100, such black is especially thick after the film.
3, some people may say, I want to print black is simply c100m100y100k100 is not blacker? No! ! ! That way there is no way to print. Because the paper's ability to absorb ink is up to 300, which means that the sum of the four values ​​of cmyk cannot exceed 300! ! I am referring to a large area.
4. It is recommended to use high-quality paper when printing large areas of black, because good paper is not so much paper gray when printing, otherwise it is easy to dirty, if the printing master is slightly careless, then there will be a lot of dirty spots printed.
5, the pre-press design is also very important, if you use a reverse white when printing a large area of ​​black, do not use too small fonts, easy to paste.
Imprinting is not allowed
Imprinting is not one of the most common and typical printing failures in printing, and overprinting is the primary indicator of print quality. What we mean by overprinting means that under different printing conditions, the overprinting error of printed matter of different quality requirements should be within the specified range. Overprinting is very helpful for improving the quality of printed products.
Imprinting is not allowed, that is, in the process of color printing, the error of the overlap of the prints exceeds the specified range. The three main forms of expression are longitudinal overprinting, lateral misregistration and vertical and horizontal misregistration.
If you want to avoid overprinting problems in printing, we must first analyze the cause of the failure. In flat-panel offset printing , printing failures that produce inaccurate overprinting are complex, but in summary they have the following main aspects:
1, that is, the adjustment of mechanical parts, improper use caused by overprinting, which is mainly manifested in the advance or lag of the printed sheet, improper adjustment of the printed sheet side, bite or bite, and unequal on both sides.
2, the printing version of the body defects caused by overprinting is not allowed, the imprinting, printing version of the original version is not standard or conditions change.
3. The deformation of the blanket causes the overprinting to be inaccurate, and the deformation of the paper causes the overprinting to be inaccurate (the paper is deformed by deformation or stretched and deformed).
4, the overprinting caused by the change of other factors is not allowed, such as the ambient temperature does not meet the requirements, the environmental relative humidity does not meet the requirements.
5, the maintenance of the machine is also very critical, the machine's fangs should be carefully maintained, cleaned, the key to overprinting.
By analyzing various faults that cause misregistration, we can use these fault analysis results to avoid overprinting during the actual printing process.
Prepress issue
According to my many years of printing experience, prepress technology is really important. If you don't handle prepress problems, you can't print high quality printing products. I will focus on the issues that should be paid attention to before printing.
1. The layout of the copy and the effective content should be more than 3MM from the cutting line, so as to avoid the text being cut when cutting.
2. The designed file should convert the text of the manuscript into a curve, so as to avoid losing text or garbled characters when the plate is not found due to the font being found.
3. Please do not use the system word when inputting text, which will cause white nodes in the intersection of strokes. Turn the font into a curve and zoom in. If there is a white node at the intersection of the strokes of the text, the font is a system word or a font that cannot be used for printing. You need to use another font instead.
4, to avoid text printing after PHOTOSHOP and bitmap software typing, bitmap text printing will appear different degrees of blur.
About color
Color cast, a headache, in the printing process, air, temperature and humidity, ink will cause chromatic aberration, so the color is only close, not exactly the same.
The hardware is the most advanced Heidelberg A105 CTP plate making and ink control technology in Germany, and the color reproduction is the international advanced level.
1. The design of the manuscript is very important. It is also important to choose the color. The color of the display or the color of the printer cannot be required. When designing, please refer to the professional chromatogram, define the color with the CMYK value of the chromatogram, and do not use the RGB mode to fill the color. Important colors must be notified to us for printing.
2, some colors are easy to cause color cast, please try not to use, such as dark green, dark purple, brown, and other four-color superimposed color.
3, text Do not use RGB color mode and multi-color overlay color, so as not to cause text blur.
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