A thermoplastic bag includes duplicative seals. In particular, in one or more implementations, a thermoplastic bag includes a first seal and at least a second seal reinforcing the same area of the thermoplastic bag. For instance, in one or more implementations, the thermoplastic bag includes multiple seals along each side edge or along the hem. If one seal fails, the other seal(s) can remain in place to prevent leaks. Thus, the duplicative seals of the thermoplastic bag can provide reinforced strength and desired aesthetics.