N-up imposition

What N-up imposition actually does

Printing several pages to a sheet is normally a checkbox in a print dialog that forgets what you told it and produces nothing you can keep. Doing it as a file is different work: the sheet size stops being whatever the printer thinks and becomes a decision, the grid has to fill in reading order, and the trim area around the edge has to survive a printer that cannot reach the paper edge. This page makes those the controls. Pick the count and the grid follows the same table the command line tool uses, so 6-up is two columns of three and 9-up is a three by three, not whatever a solver decided. Pick the sheet separately from the source, because a set of A4 pages very often has to land on letter. The outer margin defaults to 18 points and the gap between cells to 8, both editable, and the empty band they produce is what a duplex printer needs and what a guillotine cuts to. One thing this page does that a print dialog cannot: a page carrying a rotation entry is placed the way a reader sees it. A PDF stores rotation separately from the page box, so a landscape page is very often a portrait box with a quarter turn recorded beside it, and a tool that reads the box alone lays that page on its side while reporting success. The produced sheets are drawn here, page by page, with the exact size of each one printed next to them, before anything is downloaded.