Overprint a stroke or fill
You can overprint strokes or fills of any selected paths using the Attributes panel. An overprinted stroke or fill doesn’t need to be trapped, because overprinting covers any potential gaps between adjacent colors. You can also overprint a stroke to simulate a trap (by overprinting a color you’ve manually calculated as the proper combination of two adjacent colors).
Keep the following guidelines in mind as you apply manual overprinting:
-
If you use the Overprint Fill option on a 100% black stroke or fill, the black ink may not be opaque enough to prevent the underlying ink colors from showing through. To eliminate the show-through problem, use a four-color (rich) black instead of a 100% black. Consult with your service provider about the exact percentages of color to add to the black.
-
When using a stroke to trap objects (but not text characters), adjust the stroke alignment so the stroke falls outside the path or object, rather than inside or centered on the path.
-
When using a stroke to trap two spot colors or a spot and a process color, you usually apply the lighter color to the stroke, and overprint the stroke.
Use the Separations Preview panel to preview how colors will overprint.
- Select one or more paths with the Selection tool
or
the Direct Selection tool 
, or
select text characters with the Type tool. To overprint the stroke
of a path that is pasted inside a frame, you must first select the
nested (inner) path using the Direct Selection tool.
Overprinting fills and strokes
- A.
- Cyan (bottom layer)
- B.
- Magenta (middle layer)
- C.
- Yellow (top layer)