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The most important technical activity in gravure printing: trapping

Update time : 2020-09-30

Source : Zhejiang Deguang Machinery Co.,Ltd

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The most important technical activity in gravure printing: trapping

Computerized Register Rotogravure Printing Machine

In the production process of gravure printing, the most prone to problems is the phenomenon of white edges appearing at the overlap between colors. There are many reasons for this phenomenon. Since most gravure printing presses are of high-speed roller type, the substrate will inevitably be stretched and deformed under the action of pulling force, so we should take corresponding measures in the pre-production. To reduce possible problems during printing.

In order to avoid the white edges of the printed matter, two methods are usually used:
① Overprint with 100% black;
②Trapping at the junction of the two colors.

Trap is one of the most commonly used methods. In other words, trapping can be said to be the most important technology in the gravure printing plate, and it is also the most important problem. Mostly. The so-called trapping, in layman's terms, is to use color to fill in places where white edges may leak. But there is a principle for what color to use. This principle is from light to dark: white, yellow, green, magenta, red, blue, black. This must be remembered.

For example, if a yellow five-pointed star is pressed on a blue background, the yellow five-pointed star should be slightly enlarged, that is, a 0.2mm green edge should be added to the color junction. But because the green edge expands inward and outward according to the edge of the five-pointed star, we need to add an original large yellow five-pointed star to the five-pointed star with the green edge, which is equivalent to moving the yellow of the five-pointed star outward Expanded by 0.1mm.

But if, in turn, a blue five-pointed star is pressing on the yellow base, then according to the principle of going from light to dark, we should expand the yellow base to the five-pointed star. Then the green edge of 0.1mm should be placed inside the blue five-pointed star. You can cut off the five-pointed star with the green border first, and then select the original blue star to paste the inside, which is equivalent to expanding the yellow inward by 0.1mm.

Zhejiang Deguang is a professional manufacturer of gravure printing equipment. We understand various gravure printing technologies. If you are interested in gravure printing, please contact us.

Tag: gravure printing technical activity, manufacturer of gravure printing equipment