A bag for producing a foam-in-bag dunnage material comprises a closed edge portion and, in a non-sealed state of the bag, an open edge portion, the closed and open edge portions delimiting an inner bag volume. The invention proposes that a bag structure of the bag comprises a mixing chamber which is adapted to receive foam precursor substances, which is arranged within the inner bag volume, which is at least partially and initially delimited against the remainder of the inner bag volume, and which in the non-sealed state of the bag is connected to the open edge portion.