A combination chamber and external suction vacuum packaging machine operable to evacuate a vacuum bag (B1,B2) and seal closed an open margin of the bag (B1,B2), said vacuum packaging machine comprising: a base; a lid supported relative to the base for movement into and out of a closed position, said base and said lid cooperatively defining a vacuum chamber when the lid is in the closed position, said vacuum chamber being dimensioned and configured for use in a chamber packaging operation, wherein the bag (B1,B2) is entirely received within the vacuum chamber, and an external packaging operation, wherein the margin and only part of the bag (B1,B2) is received within the vacuum chamber; a vacuum source in communication with the vacuum chamber, said vacuum source being operable to evacuate the vacuum chamber and thereby the vacuum bag (B1,B2) through the open margin thereof, during chamber packaging and external packaging operations; a seal bar operable to engage and seal closed the open margin of the vacuum bag (B1,B2) after the vacuum bag (B1,B2) has been evacuated, said base and said lid presenting respective seal faces (138,164), with the seal faces (138,164) being opposed to one another and spaced apart to define a sealing gap therebetween when the lid is in the closed position; and a seal configured to span the sealing gap and sealingly engage the seal faces (138,164) during evacuation of the vacuum chamber and vacuum bag (B1,B2), said seal faces (138,164) moving toward one another to decrease the sealing gap as the seal is compressed during evacuation of the vacuum chamber and vacuum bag (B1,B2), characterized in that the lid is shiftably supported relative to the base for movement into and out of a closed position and the seal being a compressible seal and at least one of said base and said lid presenting a projecting stop configured to engage the other of said base and said lid during chamber packaging and external packaging operations to limit compression of the seal and thereby define a minimum seal gap dimension. a base; a lid supported relative to the base for movement into and out of a closed position, said base and said lid cooperatively defining a vacuum chamber when the lid is in the closed position, said vacuum chamber being dimensioned and configured for use in a chamber packaging operation, wherein the bag (B1,B2) is entirely received within the vacuum chamber, and an external packaging operation, wherein the margin and only part of the bag (B1,B2) is received within the vacuum chamber; a vacuum source in communication with the vacuum chamber, said vacuum source being operable to evacuate the vacuum chamber and thereby the vacuum bag (B1,B2) through the open margin thereof, during chamber packaging and external packaging operations; a seal bar operable to engage and seal closed the open margin of the vacuum bag (B1,B2) after the vacuum bag (B1,B2) has been evacuated, said base and said lid presenting respective seal faces (138,164), with the seal faces (138,164) being opposed to one another and spaced apart to define a sealing gap therebetween when the lid is in the closed position; and a seal configured to span the sealing gap and sealingly engage the seal faces (138,164) during evacuation of the vacuum chamber and vacuum bag (B1,B2), said seal faces (138,164) moving toward one another to decrease the sealing gap as the seal is compressed during evacuation of the vacuum chamber and vacuum bag (B1,B2), characterized in that the lid is shiftably supported relative to the base for movement into and out of a closed position and the seal being a compressible seal and at least one of said base and said lid presenting a projecting stop configured to engage the other of said base and said lid during chamber packaging and external packaging operations to limit compression of the seal and thereby define a minimum seal gap dimension.