1) select your whole page layout, then choose Edit->Copy As->PDF
2) paste onto your wireflows page.
3) set a fill colour of white, a one pixel border of mid grey, and optionally a drop shadow
You might at this point be thinking “but Andy, now I’ve pasted it as a PDF item I can’t edit it if the design changes?!” but you’d be wrong. Double clicking the pasted PDFs lets you do a linkback edit.
Toggling layers in OmniGraffle
Sometimes I need to output PDFs of a wireframe produced in OmniGraffle in two versions, one with annotations and one without. Luckily I habitually put all annotations on their own layer, so all that’s needed is a simple AppleScript to tell OmniGraffle to toggle the printable and visible nature of every layer named “Annotation”. A bit of googling turned up this forum post which does most of the work, I just needed to add in the printable property.