above referring to the drawings the headbox which is schematically illustrated in fig1 includes an inlet region 9 to which stock is continuously supplied in a well known manner this inlet region 9 extends across the entire width of the headbox the width of the headbox extending perpendicularly with respect to the plane of fig1 the stock which is thus introduced at the inlet 9 flows upwardly from the latter and then longitudinally through the interior of the headbox toward the left as viewed in fig1 so as to discharge from the aperture 8 of the headbox a plurality of water supply connections 10 are provided for the headbox at the right wall thereof as viewed in fig1 the illustrated headbox is provided in its interior with flow equalizers in the form of oblique lamellae 1 which define between themselves relatively narrow spaces or flow ducts 2 the width of these flow ducts 2 is determined by the dimensions of the spacers 3 situated between the lamellae 1 thus fig2 shows how the lamellae extend obliquely from the upper to the lower spacers 3 these spacers are in the form of groups of upper and lower relatively long bars which alternate with the upper and lower edge regions of the lamellae 1 relatively long tie bolts 7 serve to compress the upper and lower edge regions of the lamellae 1 between the several elongated spacers 3 as well to connect the side walls 6 of the headbox to the groups of upper and lower spacers 3 as well as the groups of upper and lower edge regions of the lamellae 1 situated between the spacers 3 in the manner shown most clearly in fig2.