Sure, that can be done. When you take the roll out make darn sure you don't roll the leader into the cassette. You can hear the leader coming off of the takeoff spool if you are rewinding slow enough and listening carefully. You can also feel it come off (the tension on the rewind knob will release "all of the sudden"). Then be darn sure to mark the roll with the last exposure number. Then when you put it back into the camera at a later date make darn sure that you are advancing the film in the dark (and/or with a cap, and/or at the fastest shutter speed and smallest aperture) toensure you don't doubleexpose the previously used part of hte film. Also... it is good to "waste some film" and go one or two frames beyond where you left off to ensure you don't have overlapping frames.