When you create a new document, each inputfield has a preset font. You can set these 'default fonts' yourself, at 3 different levels :

• Global (Extra -> Settings)
  also see: Settings
  
  
• Per documenttype (via documenttype editor)
  also see: Tabpage general data
  
  
• Per field (via documenttype - field editor)
  also see: Tabpage general data

The default font you setup for the field, overrides the default font of the documenttype. The default font of the documenttype overrides the global default font.

Changes you make to default fonts will only be visible when you create a new document. Also, if you make changes to the global font, but the documenttype itself also has a default font, no changes will be visible because the documenttype font overrides the global font.