Printing with multiple pages

First, put n pages at each leaf with mpage comman:

$ mpage -n a.ps > b.ps

* n can to be 2, 4 or 8

To reverse the pages:
$ pstops "2:0@1.0(-0.00cm,0.0cm),1U@1.0(21cm,29.7cm)" b.ps > c.ps