Abstract: This invention relates to an improvement in the process for shirring cylindrical tubular casings, especially artificial sausage casings of synthetic material, in which an inflated casing is conveyed in the direction of its longitudinal axis and shirred, with pleating, against a counter-force by shirring forces acting upon the circumference of the casing, the improvement comprising that the forces acting upon the surface of the casing do so continuously and simultaneously, at equal intervals, at a plurality of points on at least two straight lines extending parallel to and symmetrically about the longitudinal axis of the casing, the action being at right angles to the longitudinal axis of the casing, and, simultaneously, in the direction of the longitudinal axis of the casing, against the counter-force. The invention also relates to an apparatus for performing the process.