Global Graphics supports PDF Processing Steps (ISO 19593-1) in the latest version 12.1 of their Harlequin RIP. This is a new ISO standard designed for labels and packaging workflows, that specifies a standard way of encoding processing steps such as die and fold lines or dimensions into a PDF file. It provides an unambiguous way of marking the technical content that’s required in the finishing step of the production workflow but not intended to be printed.
The benefit to converters is that they can automate common digital press workflows, such as starting a print run with a few iterations of just the cut and fold lines for checking registration with dies and other finishing equipment. The main print run will then usually need all the processing steps turned off, so just the live graphics are shown and there’s no risk of cut lines being visible on the final print. A few more copies of just the technical separations may be printed at the end to detect if registration with cutters and converting equipment has drifted during the job.