Abstract: Apparatus for obtaining a predeterminable distribution of weight per unit area in the transverse direction of a mat formed on a movable support for the manufacture of chip board, fiber board and similar boards is described by means of which fluctuations of the raw material composition and fluctuations of the chip geometry can be compensated for, having regard to the retention of a desired distribution of weight per unit area, by varying the thickness of the pre-mat or mat, or, in the case of a mat which is built up of a plurality of layers, of at least one of the mat layers, at least region by region, by mechanical action over the width of the mat in dependence on a desired distribution of the weight per unit area over the width of the pre-mat, or of the mat or of the mat layer.