Abstract: Empty, flat folded storage bags which may be valve bags are prepared for filling with a flowable material, by seating and stacking a plurality of the bags on a fixed elevation base within a chamber of a bag holding magazine assembly, the resulting stack defining an initial stack rising from a lowermost one the bags on the base to an uppermost one of the bags. In a first cycle of operation, all but the lowermost bag is raised away from the base, the raised bags defining a depleted stack of bags. Then, while the depleted stack remains raised, the lowermost bag is removed from the chamber through a chamber outlet opening. Then, the depleted stack is lowered to seat a new lowermost bag on the base to complete first cycle. The cycle is repeated for each lowermost bag.