When duplex printing, it's important to select the correct edge orientation. This will ensure that your pages line up and the page sides aren't opposite orientations. If you're printing in a left-to-right read language, you will select "top-left." There are additional settings for layout types.
Portrait
To print portrait-layout duplex, you will need to select "long-edge."
Landscape
To print portrait-layout duplex, you will need to select "short-edge."
These simple steps will ensure you have an easy to read print.