Community

Printed documents occupy only about 1/4 of the page and the characters are very small.

I've done:

Configure -> Preferences -> Document Classes -> Document Class > Font and selected the desired Font, Font Style and Size then clicked OK but the results are unchanged.

What am I doing wrong?

I'm not sure, but try clicking View->Document Properties->Font to make sure the font you've specified in Preferences has in fact taken effect.

Have you checked that the Scope radio button on the Font tab is set to either Printer or Both?

Also, click File->Page Setup to make sure your margins are set correctly.

Does the output look correct when you use Print Preview?

Have a look at this thread.