Abstract: The invention is a sheet feeder including a skimmer and a separator. The separator is designed for advancing the engaged sheet while separating any adjacent sheets. In one embodiment, the separator has a driven infeed roller nipped with a drag or separator roller. The separator roller also includes a recoil mechanism. The drag normally slips and permits the separator roller to be driven forward by the infeed roller, which cocks the recoil mechanism, then allows the infeed roller to advance a sheet. The separator roller recoils backward when a multifeed of two or more sheets is engaged between the advancing and separator rollers. The sheet separator can have as its sheet-engaging member a roller sleeve. The roller sleeve can be axially slidable on the rotatable element for ready installation on and removal from the rotatable element.