A sheet-feeder system for multiple feeding of magnetizable sheets from a stack through a portable magnetizer designed for on-site use, enclosed in a portable case which is hand-carryable. A sheet advancer advances single magnetizable sheets from the stack in a stack positioner. The sheet advancer includes a single-sheet separator configured to separate single magnetizable sheets from the stack during advancement. Magnetic attraction between a magnetizable sheet and a magnetic field generated by a sheet magnetizer configured to permanently magnetize single magnetizable sheets as they are advanced by the sheet advancer assists the sheet advancer to advance the single magnetizable sheets from the stack through the sheet magnetizer.