The use of whitening pigments comprising (a) a melamine-formaldehyde or phenol-formaldehyde polycondensation product and (b) a water-soluble fluorescent whitening agent of formula (1), wherein R1 and R2 are each independently of the other —OH, —Cl, —NH2, —O—C1-C4alkyl, —O—aryl, —NH—C1-C4alkyl, —N(C1-C4alkyl)2, —N(C1-C4alkyl)(C1-C4hydroxyalkyl), —N(C1-C4hydroxyalkyl)2, or —NH—aryl, for example aniline-mono- or -di-sulfonic acid or an anilinesulfon-amide, morpholino, S—C1-C4alkyl(aryl), or a radical of an amino acid, for example aspartic acid or inimoacetic acid, which radical is substited at the amino group, and M is hydrogen; sodium; potassium; calcium; magnesium; ammonium; mono-, di-, tri- or tetra-C1-C4alkylammoniun; mono-, di- or tri-C1-C4hydroxyalkylammonium; or ammonium di- or tri-substitue by a mixture of C1-C4 alkyl and C1-C4hydroxyalkyl groups, for whitening paper coating compositions.