A large round baler is equipped with an enveloping arrangement that moves a run of enveloping material to the circumferential surface of a bale with a pivot arm including a driver having projections in the form of teeth that can be caused to penetrate the enveloping material to cause a positive locking with the run of enveloping material so that the enveloping material may be selectively inserted into the baling chamber at the beginning of a wrapping cycle and engaged with a contact plate to effect separation of the enveloping material once a predetermined number of wraps have been applied to the circumference of the bale.