Abstract: An apparatus for bottom folding and stacking of continuous strip of pre-folded paper is disclosed in which a reciprocating frame having a pair of belts defining a gap therebetween is reciprocated within a stationary frame beneath a pair of spaced-apart edge guides. Each belt is supported on a set of transverse rollers journalled in the inner frame and is preferably affixed at both ends to its respective edge guide.Pre-folded paper strip continuously fed from a printer is drawn upwardly through the gap as the gap is reciprocated between the edge guides and is folded and stacked at the bottom of the stack, thereby allowing paper first printed to be inspected or removed without disturbing the stack.