(v13) Interaction with transparency

This page applies to Harlequin v13.1r0 and later; both Harlequin Core and Harlequin MultiRIP.

Internally, OverprintPreview is implemented by varying the properties of an implicit transparency page group, or virtual device; the details depend on which option is chosen. The virtual device is created by the RIP for the purpose of compositing on all pages of all PDLs that do not have an explicit transparency page group. The transparency color management features are described in detail in (v13) Transparency color management, and these also apply when OverprintPreview is active. In this context, overprinting when OverprintPreview is active can be seen as a form of compositing.

OverprintPreview does not affect PDF pages with an explicit page group; they are always treated as though OverprintPreview is in Transparency mode. More precisely, the PDF page must have a CS entry in the page’s Group dictionary.

OverprintPreview only has an effect on jobs submitted in other PDLs, and PDF pages not covered by the above. PDF jobs containing transparency may be affected by OverprintPreview when a page group does not have a CS entry.