Abstract: A bag, for e.g. collecting garbage or freezing foods, includes a thin, flexible material, e.g. plastic foil formed with an opening, which in its flat-laid state is bounded by two facing edges. A flexible stiffener made of plastic or a similar material is attached along each of these edges. The two stiffeners are connected with a foil hinge at their ends. The bag is furthermore provided with means to bend the stiffeners in a direction opposite to each other. A single operator, without the risk of soiling his or her fingers, can quickly and easily fill the bag.