Now that the Portable Document Format has become a predictable, platform-independent, page-independent entity, which solves many of the limitations of PostScript, we must tackle other print-related workflow issues.
Issues such as trapping, imposition and OPI (picture replacement) play an important role in the success of PDF as a link to the completely digital workflow for the high-end printing and publishing world.
The very essence of digital workflow for printing and publishing involves the integration of many process steps.
The most common processes include: preflighting, trapping, imposition, and OPI serving.
From manual techniques, each of these steps has evolved to
computer operation with manual intervention and now totally automated approaches.