What is trapping?
ack in the days when there were a lot more people involved with the production process, a designer never got close to the whole process of trapping. But, as the walls started to come tumbling down, technology knocked people like film-strippers and many pressmen out of their jobs. These were the people who did things like trapping, so it seemed like the responsibility would fall on the designer. After all, the designer was responsible for every other aspect of setting up electronic files correctly. Why not trapping? Thank goodness it didn’t work out that way. What is trapping? Have you ever looked at a printed piece and noticed that one of the colors is off just a little that things aren’t lining up perfectly? It’s a common thing. With printing presses running as fast as they do and with paper being fed from big rolls and big stacks, it would be nearly impossible for every printed impression to register absolutely perfectly. Most people won’t notice a hair’s difference in register and t
Trapping is the process of ensuring that any two adjacent colors overlap slightly so that any misalignment during the printing process does not cause unsightly white gaps between those two colors. It is important to note that you don’t always need to trap adjacent colors. Two adjacent colors that share a component process color need not be trapped. For example, a green object immediately next to a cyan object need not be trapped because both contain the component color cyan. Likewise, a blue object next to a red object need not be trapped. As a result, the cyan negative, and subsequently, the cyan printing plate cannot possibly have a white gap at that point (see Figure 27). In this figure, though most of it need not be trapped, there is only one potential trouble spot, and that is the junction of all three colors. This can easily be solved by putting a trap between the two rectangles.
