a self - threading cassette for strip material and system for loading same is effective to tightly wind extended length materials of various types . no special adherent and interengaging surface characteristics are provided on a takeup reel within the cassette or on the strip material itself . tightening of the lead ends of the strip material is achieved , according to a preferred embodiment , through the use of a takeup reel having at least portions of a high coefficient of friction material which cooperates with a leaf spring that is partially coiled about the takeup reel in a manner so as to cause the lead end of the strip material to coil about the takeup reel and gradually tighten thereon .