Abstract: The invention relates to a method for separating particulates out of filtrates of a paper, cardboard, paperboard or pulp production plant and for reapplying the separated particulates to a surface of paper, cardboard or paperboard, comprising at least the following steps: a) separating the particulates out of the filtrates at a size of less than 1200 pm, b) coagulating the separated particulates of same, c) as applicable, mixing the separated particulates with further particulates from a paper, paperboard or pulp production, and/or microfibrillated cellulose (MFC), d) forming an aqueous suspension from the particulates, e) as applicable, adding to the suspension further additives for the surface treatment of paper or paperboard, selected from native and oxidatively degraded starch or calcium carbonate, f) homogenously applying the formed suspension to a paper or paperboard surface in a quantity between 0.5 and 30 g/m2, in particular 4 and 15 g/m2, and g) drying the paper or paperboard.