Ground Controls->Non_PDF->Trapping->Text


Overprint - This Ground Control will trigger if text trapping has been set to overprint in a QuarkXPress document. Black text is set to overprint by default. An example of where overprinting text can be problematic is if you have white or paper colored text and place it over an image and then set the text to overprint. This will cause the text to become less than 100% opaque, or transparent when processed by a RIP and the text will either disappear or become very faint.


Knockout - This Ground Control will trigger if text trapping has been set to knockout in a QuarkXPress document. When text is set to knockout, it acts like a cookie cutter and cuts out everything below it color-wise, so the actual paper color shows through. If text is made up of more than one CMYK component value and is small, any misalignment during a press run will show as a halo of color.


Auto - In Quark you can set a default value in the Preferences for Auto Amount. By default this value is 0.144 points. Whatever the value you set, the Ground control will trigger if text trapping on Quark is set to either Auto Amount (+) or Auto Amount (-).


Custom - This Ground Control will trigger if text trapping has been set to Custom. In Quark by default this causes the text to knockout.