Abstract: Methods of making flexible packages having an openable and resealable interlocking closure from a continuous web of flexible film, the closure being formed transversely to the direction of film flow at the consumer preferred position across one end of the package during package formation at line speed. The system utilizes a converter device mounted atop or adjacent to standard packaging apparatus to form a small amount of the running packaging film into the resealable closure structure as an integral part of the film extending transversely to the long dimension of the package. The converter functions with both horizontal and vertical form/fill/seal wrapping machines and with overwrap packagers, and uses diverse packaging films.