% sudo perl -pi -e 's/^papersize a4/papersize letter/' \
/usr/share/groff/1.18.1/font/*/DESC
If you edit the /usr -> share -> groff -> 1.18.1 -> font -> devps -> DESC file, you can change the font family to "H" or "P". That will make Helvetica or Palatino, respectively, your default font. I like Palatino.
But why use groff?
The best use I have for groff is printing man pages. If I want to print, for example, the ls man page, I can run this from a Terminal window:
% groff -man /usr/share/man/man1/ls.1 | ps2pdf - ls.pdf
Then I can open and read or print the ls.pdf file. This beats the heck out of printing plain text.But how do I know what file to print?
Type man -d ls and on the last line of output, you'll see what file it would have displayed. Then supply that file name as an argument to groff as shown above, and you can get a pretty man page out of it.

