If you have an Acrobat question, ask questions and get help from one of our experts. changing default font settings for text field forms. I am making a PDF template with text field forms. I have changed the font settings in Adobe/Preferences to Arial size 8. Yet when I make a text field, the settings are helvetica 12. Changing this to Arial 8 adds 500KB in weight per merge field (total fields 130!) so the developers are complaining that the size is too large.