Quick note on adding a truetype font or fonts to Ubuntu Linux (also applies to Debian and perhaps some other distros too).

cd /usr/share/fonts/truetype     (presumably this could be done in /usr/local/share/fonts/truetype, instead)
sudo mkdir myfonts
cd myfonts
sudo cp ~/*.ttf .
sudo chown root.root *.ttf
# Might also need to:  "sudo mkfontscale" (or "sudo ttmkfdir" - seems to be an older by slightly different implementation) to generate fonts.scale
sudo mkfontdir
cd ..
Edit fonts.cache-1 and add new line: "myfonts" 0 ".dir"
then: sudo fc-cache

Not sure if this this "proper" way to add fonts, but it seems to work! --- comments welcome.