Derrick Moser - 2017-12-26

Jeff,
The font size used by Diffuse can be changed via the preferences dialog (select the "Edit -> Preferences" menu item).   The first item in the "Display" section is labeled "Font".   This item lets you change the font (including the font's size).  Diffuse will re-render the panes with the new font once you press the "OK" button on the preferences dialog to accept the changes.

Cheers,Derrick