Foldable bottle with fastening element

A blow molded bottle having at least two opposed, spaced side walls, and an upper end containing a pouring neck having therein a circular opening communicating with the space between said two opposed, side walls of the bottle, said bottle being made of pliable material which enables the lower end of the bottle to be folded repeatedly upwardly toward said upper end thereof from an undeformed configuration into a deformed, multi-fold configuration of limited size, and a flexible fastening element to hold the bottle in the deformed configuration, and characterized in that the bottle is made of blown plastic material having formed in a portion of said upper end of the bottle a groove located adjacent to one side of said pouring neck and extending transversely of the axis of said pouring neck, and in a direction crosswise of the folds produced in the bottle in its deformed configuration, said groove being disposed to receive and retain therein crosswise of said folds a portion of said fastening element when said element is employed to hold the bottle in its deformed configuration.