A folder (58) of the type having a folding cylinder (16) cooperating with a jaw cylinder (20) to cut and fold a ribbon of paper (14) into a folded product (14') provided with a guide assembly (60) with a guide surface defined by a nonconcentric guide with a convex section (64) and a convex section (74) joined together end-to-end to form a generally S-shaped or approximately cubical parabolic guide surface which conforms to the natural flow shape of the product (14') for minimum interference therewith to reduce the formation of dog-ears.