Abstract: A compactable luggage system includes a portable container having an internal storage compartment structured and arranged to store at least one travel item, an one outer-volume reducer structured and arranged to reduce an outer volume of the portable container. The portable container includes a pressure-tight barrier structured and arranged to bar equalization of fluid pressures across the pressure-tight barrier surrounding the internal storage compartment, and a re-sealable access structured and arranged to provide re-sealable access to the one internal storage compartment through said pressure-tight barrier. The portable container includes a pressure-dependent volume adjuster structured and arranged to adjust the outer volume of the one portable container in response to the fluid pressure differential across the pressure-tight barrier. This and other features are described.