Tool for producing a container composed of plastic in a thermoforming process, in particular a plastic deep-drawing process, with a positive mould, comprising - a base section for forming a container base, - a side-wall section for forming a peripheral side wall which is formed to be of the same material as the container base, - a wall for forming a stacking edge which is in the form of a hollow profile and which projects beyond an outer contour of the side wall of the container in a manner running around an entire container outer side and which, inwardly towards a container inner side, is in the form of an open groove and which is arranged spaced apart from the container base, wherein - the wall, in a moulding position for moulding of the container, is arranged so as to protrude in a manner running around an entire outer side of the positive mould, and an angle (α) of less than 90° is formed between a wall side directed towards the base section and a region, extending from this wall side in the direction of the base section, of the associated side-wall section, and wherein - the wall is movable from the moulding position into a demoulding position, in which a distance (d) of an end, protruding in the moulding position, of the wall from the side-wall section is reduced, characterized in that - the wall comprises multiple wall segments (14.1 to 14.4) which are in the form of slides and which, from the moulding position, are displaceable into an interior of the positive mould, and - wall segments (14.5 to 14.8) arranged at corners of the side-wall section are in the form of gravity slides, which, in the moulding position, are blocked by the side-wall section and adjoining wall segments (14.1 to 14.4) in the form of slides and, after displacement of adjoining wall segments (14.1 to 14.4) in the form of slides into the interior of the positive mould, are released such that, during the demoulding, they move into the interior of the positive mould of their own accord owing to the weight force. - a base section for forming a container base, - a side-wall section for forming a peripheral side wall which is formed to be of the same material as the container base, - a wall for forming a stacking edge which is in the form of a hollow profile and which projects beyond an outer contour of the side wall of the container in a manner running around an entire container outer side and which, inwardly towards a container inner side, is in the form of an open groove and which is arranged spaced apart from the container base, wherein - the wall, in a moulding position for moulding of the container, is arranged so as to protrude in a manner running around an entire outer side of the positive mould, and an angle (α) of less than 90° is formed between a wall side directed towards the base section and a region, extending from this wall side in the direction of the base section, of the associated side-wall section, and wherein - the wall is movable from the moulding position into a demoulding position, in which a distance (d) of an end, protruding in the moulding position, of the wall from the side-wall section is reduced, - the wall comprises multiple wall segments (14.1 to 14.4) which are in the form of slides and which, from the moulding position, are displaceable into an interior of the positive mould, and - wall segments (14.5 to 14.8) arranged at corners of the side-wall section are in the form of gravity slides, which, in the moulding position, are blocked by the side-wall section and adjoining wall segments (14.1 to 14.4) in the form of slides and, after displacement of adjoining wall segments (14.1 to 14.4) in the form of slides into the interior of the positive mould, are released such that, during the demoulding, they move into the interior of the positive mould of their own accord owing to the weight force.