I like to use rather small fonts, DejaVu Sans 8 @ 86 DPI, this suits me perfectly, however some apps seem to use even smaller fonts for certain elements, such as the notify bubbles where the headline looks fine but the text below is even smaller, probably size 7, the same goes for Gwibber and Tomboy and Software Centre.
Here's a screenshot of what I mean:
So my question is, how do I change the size of these smaller fonts? I recently spent a week in Kubuntu and all fonts were configurable including 'small' fonts. How do I do this in Ubuntu?
PS: I know how to go into Appearance > Fonts. What I'm looking for is not there.