It is still necessary to print documents. Many printers are able to print one side of the sheets, here I describe the procedure to print both side correctly. The procedure depends on the kind of printer.
Make an empty .pdf page:
$ echo '' | ps2pdf -sPAPERSIZE=a4 - white.pdf
Add an empty page at the end of a document:
$ pdftk W=white.pdf D=input.pdf cat D W output output_file.pdf
Extract even-numered pages from a document (replace the word even with odd for odd-numered pages):
$ pdftk input.pdf cat 1-endeven output_even.pdf
Reverse the order of pages:
$ pdftk input.pdf cat end-1 output output_reversed.pdf
PPPP the printed face, and
WWWW the blank face it is the case 1 if printing a three pages document the sheets end up like this:
PPPP 3 WWWW PPPP 2 WWWW PPPP 1 WWWW
In other words, the printed pages end up with the face up and the order of the sheets is reversed.