A method for manufacturing a bag for use in vacuum packaging comprises forming a first panel having a plurality of baffles for evacuating air and/or other gases from inside the bag using a suction source, while preventing liquids from being drawn into the suction source, and a second panel. Each panel comprises a gas-impermeable base layer and a heat-sealable inner layer molded from melt-extruded resin. The first panel is overlapped with the second panel, and three of four edges of the panels are heated such that the inner layers bond at the heated edges. This description is not intended to be a complete description of, or limit the scope of, the invention. Other features, aspects, and objects of the invention can be obtained from a review of the specification, the figures, and the claims.