What is overprinting?
If two colored elements are superimposed in the print file, there are two options: overprinting or choking.
Generally, the object on the top will be printed normally and the object on the bottom will be knocked out in this place. Hence, only those parts not hidden by the object on the top will be printed of the object on the bottom.
In overprinting, both objects will be printed over each other. This leads to a mixture of the top and bottom colors where the objects are superimposed. However, many programs do not show these color overlaps in the standard settings leading to this not becoming apparent when designing the print files.
When is overprinting desirable?
Generally: Our system will automatically set black text with a font size of below 12 pt to “Overprint”. Other small-area elements such as black lines should also be defined as overprint. The overprinting effect can be used as a design element in particular with colored areas.
Checking overprint settings in the PDF
In Adobe Acrobat you have the possibility of activating “Overprint preview”. This allows you to check the overprint settings. Especially with catalogs or other comprehensive print products it is worth checking all pages.