A Printing Proof produces a watermarked pdf suitable for running printer tests.
It is not custom watermarked, and allows you to configure printing options.
Choose to render only to the trim line, or extend to include the bleed area and crop marks as well.
Render the pages as full double spreads, or split doubles into sides
Choose to render one file for all pages, to render each page as a separate file, or to split the cover as a separate file from the rest of the book.
The rendered pdf will be saved to Documents\Memento\Projects\Proof PDF by default.