Abstract: Flexible films, packages, and methods of making the same are provided where the film is capable of being sealed to itself or to other films by more than one sealing method, including thermal sealing and ultrasonic sealing. In particular, a package includes at least three multilayer films sealed together with an ultrasonic seal, where the outer layers remain intact and do not contain visible perforations at the ultrasonic seal. The multilayer films include at least a sealant layer and an outer layer, and may be separate pieces of multilayer films or one multilayer film that has been folded. A method for sealing a film includes the steps of providing a multilayer film having at least a sealant layer and an outer layer, folding the multilayer film to provide a folded film including at least three layers of multilayer film, and applying mechanical oscillations to seal the folded film.