do it right

lib/lettering/font.py

@@ -185,7 +185,7 @@ class Font(object):
         custom_dir = get_custom_font_dir()
         if not custom_dir:
             return False
-        return get_custom_font_dir() in self.path
+        return custom_dir in self.path
 
     def render_text(self, text, destination_group, variant=None, back_and_forth=True, trim_option=0, use_trim_symbols=False):