Trapping

When you can't avoid touching colors and overprinting black is not a viable option, you may have to deal with trapping. If you are very inexperienced with trapping or have a complex image to work with you might choose to turn over the job of trapping to your service bureau. Otherwise, you'll need to manually trap your images or use the auto-trapping features of your software.

If you choose to trap your images you'll first want to learn some of the basic terminology. Even when someone else is doing the trapping, it is helpful to understand what is involved. The next few pages of this tutorial illustrate chokes, spreads, knockouts, and overprinting or surprinting.