These very versatile slitter/rewinders were invented in order to slit certain substrates which cannot be wound on a single shaft. These materials, such as most films, will interweave or create other problems unless the slit cuts are alternated up and down on two rewind shafts. Often each slit cut is affixed to the rewind shaft through a series of spacers which act as clutches, allowing each roll to wind correctly. These winders can use score slitting, shear slitting, or razor slitting methods.