Comment by kragen

You're talking about Kujala's 4×6 font, then, but you have it wrong; three letters of text are 12 pixels wide in it. There's no extra implicit spacing pixel, either horizontally or vertically.

As you can see from the code in http://canonical.org/~kragen/sw/dofonts-1k.html, moving to the next character position is "x += 4" and moving to the next line is "x = 0\n y += 6".