darktable framing module help

I export my larger images to print at a commercial printer. The last job, the printer got it wrong and the print was too small.
Is there a way to tell the frame module to put a border by size.(inches/cm), and have a line identifying the edge of the print.
I don’t see much in the manual, and very little anywhere else.

Sounds like you want trim/crop marks, but I don’t think we support those.