Font fallbacks:
Primary font: 'Helvetica', Arial, sans-serif;
Primary font italic: 'Helvetica', Arial, sans-serif;
Primary font bold: 'Helvetica', Arial, sans-serif;
Webfonts:
Primary font: 'MyFont', 'Helvetica', Arial, sans-serif;
Primary font italic: 'MyFontItalic', 'Helvetica', Arial, sans-serif;
Primary font bold: 'MyFontBold', 'Helvetica', Arial, sans-serif;