Air bag with a vent

An inflatable air bag (10) for restraining a vehicle occupant (14) includes woven air bag material defining a chamber (20) into which inflation fluid is directed to inflate the air bag (10). The air bag material (10) has an opening (30) for venting fluid from the chamber (20). Reinforcement material (36) is fixedly secured to the air bag (10) and surrounds the opening (30) in the air bag material (10). The reinforcement material (36) has a weave orientation (52) that extends at an angle to a weave orientation (50) of the air bag material (10). Orientation means (40, 42) on the air bag (10) and the reinforcement material (36) help ensure that the weave orientations extend at an angle to each other.