Methods of incrementally stretching thermoplastic films in the machine direction include elongating the films in the machine direction without reducing the films' machine-direction tear resistance. In one or more implementations, methods of incrementally stretching thermoplastic films include reducing the gauge of the films without reducing the films' machine-direction tear resistance. The methods can involve cold stretching the films and imparting transverse-direction extending linear rib pattern into the film. The linear ribs can have alternating thick and thin gauges. Incrementally stretched thermoplastic films can have a machine-direction tear resistance that is approximately equal to or greater than the machine-direction tear resistance of the film prior to stretching.