I've got a RTF-textfield with the font and fontsize set to Arial and 8pt.
But when a user copy and paste text from an other application with other fonts and fontsizes, this wil be pasted too.
Is there a way to manipulate the font and fontsize for this field when the user exits the field?
If you do not want to allow custom styling in your field, then you do not need a Rich Text field. Rich text is stored as XHTML, which may make if difficult to modify programmatically.