A crease plow folder for folding a sheet or continuous web of sheets comprises a non-twisting, holding and transporting mechanism for holding and transporting the sheet or continuous web of sheets in a non-twisting fashion during folding of the sheet. The crease plow folder first creates, at a score line in the sheet or sheets, a rolling fold by directing the sheet or sheets between a centerline-twisted bar and a pressure bar. The rolling fold is then converted into a creased fold by moving the sheet or sheets between a crease roller and an idler roller, thereby generating a change in direction that results in the crease. A controller and associated sensors are included for monitoring the progress of the sheet through the plow folder and for detecting any skewing of an entering sheet.