Thanks for the response. I'll look into line-spacing.
What I'm doing is making a presentation mode (
https://bitbucket.org/zck/zpresent.el;, available on Melpa) that presents from Emacs. I want to be able to, for example, make a title slide that looks like this (monospaced font required for this to look right):
+-----------------------------
---+
| |
| |
| |
| Title goes here! |
| |
| $DATE by $PERSON |
| |
| |
+--------------------------------+
I'm certainly open to other ways of making this look right. I don't think doing calculations in pixels would work, unless there's a way to insert text at a specific pixel inside Emacs. And even if there were, that seems like a bunch more work to basically reproduce LaTeX.