Abstract: In the manufacture of a packing container laminated packing material is used which with the help of a rotating cylindrical cutter is made thinner within a limited longitudinal region. This reduction of thickness has been difficult to realize up to now with the desirable accuracy, since the specified depth of cut that has been set may readily be influenced by vibrations in the moving material or in the cutter. These difficulties are overcome by a guiding device, arranged in the immediate vicinity of the edge of the cutter, which limits the thickness of the strip cut away. The guiding device is suspended in contact with the cutter in such a manner that not only are the vibrations reduced, but also the influence of the remaining vibrations on the depth of cut is minimized. The guide is adjustable to vary the depth of cut and includes air outlets for cooling the cutter and for guiding the cut strip away from the packing material.