Using the Trap commandThe Trap command creates traps for simple objects by identifying the lighter-colored artwork--whether it's the object or the background--and overprinting (trapping) it into the darker artwork. Note: The Trap command is only available when you are working on CMYK documents. ![]() What the Trap command does A. Area of overprinting B. Area of knockout C. Background color D. Foreground color You can apply the Trap command from the Pathfinder palette or as an effect. For more information on effects, see Using filters and effects. For instructions on using the Stroke palette to create a trap with strokes on individual objects, see Trapping by overprinting.
In some cases, the top and bottom objects may have similar color densities so that one color is not obviously darker than the other. In this case, the Trap command determines the trap based on slight differences in color; if the trap specified by the Trap dialog box is not satisfactory, you can use the Reverse Trap option to switch the way in which the Trap command traps the two objects. ![]() Light object and dark background (Trap command creates spread) compared to dark object and light background (Trap command creates choke) To create a trap using the Trap command:
Specifying different horizontal and vertical trap values lets you compensate for on-press irregularities, such as paper stretch. Contact your print shop for help in determining this value. The default value of 100% results in the same trap width on horizontal lines and on vertical lines. To increase the trap thickness on horizontal lines without changing the vertical trap, set the Height/Width value to greater than 100%. To decrease the trap thickness on horizontal lines without changing the vertical trap, set the Height/Width value to less than 100%. ![]() Height/Width set to 50% (left) compared to 200% (right) The Tint Reduction value reduces the values of the lighter color being trapped; the darker color remains at 100%. The Tint Reduction value also affects the values of custom colors. ![]() Tint reduction value of 100% (trap contains 100% of lighter color) compared to tint reduction value of 50% (trap contains 50% of lighter color) |