normal text layout, more readable but uses more paper <-> dense text layout, less readable but fewer pages

A6 - Portrait (good for Kindle)

A5 - Portrait

US Half-Letter - Portrait

For duplex print, configure your printer to flip on short edge.

A4 - Booklet

US Letter - Booklet

If you don't have a duplex printer.

A4 - Two Page

US Letter - Two Page