The interface has two main parts. Along the top is a set of menus that
correspond to the different components of an X font name.
-foundry-family-...
You can select values via these menus. The second part is a listbox
that displays all possible fonts on your system. When you make a menu
selection, the first matching font is selected in the listbox. A sample
of the font is shown at the bottom of the interface. You can also just
select a font directly from the listbox. At the end of the listbox
is a set of short names for fonts. If you want to easily find a bigger
font, try fonts like 9x15 or 8x13.
When you find a font you like, select the resource you want to set from the Widgets... menu. The Widgets... menu lists resources, and in turn the resources affect the widgets. You can set the font for everything by setting the *font resource, which is at the top of the list.
*font sets the font for everything. You can then adjust the font for more specific widgets with the other settings.
*Button.font sets the font for all kinds of buttons, plus menus. If
you really want different fonts for different kinds of buttons or menus,
then you'll have to set the resources by hand. You'll need to tweak
*Checkbutton.font
*Radiobutton.font
*Menubutton.font
*Menu.font
Note that there are some additional preference settings under MIME that affect the font size of certain MIME messages. If you really want to get into the details, consult the app-defaults file for ways to define fonts for different character sets. The overall font situation in exmh is somewhat messy, so I apologize for the clutter.