Application of image trapping in screen printing

Image trapping is the intentional overprinting of different colors so that they meet on the surface of the paper. Different factors such as ink roller deinking, image output, plate making, printer maintenance, paper movement, and environmental conditions often result in inaccurate positioning on the press. Image trapping is the pre-compensation for this phenomenon.

If trapping is not done, an unpleasant white gap will appear between images when misregistration occurs between colors. The trapped image area is set to be too large or too small to make the shadow and color parts darker. For example, if a four-color picture encounters a black border, the black border must maintain its shape, while the yellow, magenta, and cyan of the picture must be larger and overprinted onto the black border. In the process of making films and preparations, we can achieve trapping through "extension and indentation".

Reprinted from: China Washing & Dyeing Industry Information Center