Walk on the only way, paper printing supplier.
Principles and methods of trapping
Jul 20,2021
The implementation of trapping should also follow certain principles. Under normal circumstances, it is to expand the color without expanding the color, expand the light color without expanding the dark color, and expand the flat net without expanding the field. In some cases, mutual expansion can be carried out. In special cases, reverse trapping is required, and even a gap between two adjacent colors is added to compensate for the overprinting error, so as to make the printed matter beautiful.
The size of the trapping volume depends on the characteristics of the printing material and the overprint accuracy of the printing system. Generally, the trapping volume of offset printing is smaller, and the trapping volume of gravure and flexo printing is larger, generally 0.2~0.3mm, which can be determined according to the customer's printing accuracy or requirements.
Common trapping processing methods
(1) Single-color line overprinting method: add light-colored lines on the side of the color block, and select the line attribute as overprinting.
(2) Synthetic line method: add synthetic line on the edge of the color block, and the line attribute is not selected as overprint.
(3) Layering method: trapping is achieved by shrinking or expanding elements on different layers.
(4) Shifting method: by moving the position of the inflection point in the color block to achieve inward shrinking or outward expansion, generally used in trapping related to gradation.
White trapping
In plastic packaging printing, white ink is widely used. Generally, in the printing of transparent or translucent plastics, it is necessary to use white as a base, and sometimes two layers of white are also supported. In order to prevent the white under the color block from being exposed due to inaccurate overprinting, the white retraction should be considered before printing.
1. The white retraction can be carried out according to the depth of the color on it or the customer's requirements, and the retraction amount is generally 0.2~0.3mm.
2. If the color block is white and the side is transparent, the white color can be retracted into the color block by 0.3mm.
3. When the black or gold is under the white, the white can retract 0.5~1mm into the black and gold.
4. If the color block is lighter or flat screen, the white shrinkage should be small or not shrink. For example, when the dot percentage of the color block is between 30% and 50%, the shrinkage of the white color can be 0.15mm; and when the dot percentage of the color block is less than 30%, the white color may not shrink.
5. When supporting the white under the gradient pattern, the white should be considered to be retracted diagonally. The cyan gradient supports white, the white area with dark cyan color shrinks by 0.2mm, and the white area with light cyan color shrinks by 0.1mm, which can be found by shifting the inflection point.
PREVIOUS:
NEXT:
Contact Us
E-mail:
ty@tengyuechina.com
Phone/WeChat:
+86-13725577064
Address:
NO4 Building，Fengye 4th Road，Fenghuang Community，Fuyong Street，Bao'an Districtm，518103，Shenzhen，Guangdong，China.
Shenzhen Tengyue Printing Co., Ltd.
Tel: +86-755-27369975-812
Mobile:Mr. Zhan +8613725577064
Mobile:Molly +8618200702381
Email: ty@tengyuechina.com
