Optical brighteners (P.sub.AB) of formula ##STR00001## wherein each n independently signifies 1 or 2, the group SO.sub.3M shown with the floating bond is linked to the position 4 or 5, each M independently signifies an equivalent of a non-chromophoric cation, each M' independently signifies hydrogen or M, at least a part of the cations M of (P.sub.AB) are cationic groups of a polycationic polyol/epichlorohydrin/amine polymer (P.sub.A), which contains quaternary ammonium groups in salt form as heteroatomic ring members or chain members, any others being cations selected from alkali metal cations, unsubstituted ammonium and ammonium substituted with C.sub.1-3-alkyl or/and C.sub.2-3-hydroxyalkyl, the polycationic polymer (P.sub.A) is a polymer which is at least in part crosslinked over one or more of its quaternary ammonium groups, any other counterions to the cationic groups of (P.sub.A) being non-chromophoric anions of low molecular acids, and the ratio of the total anionic groups in the anionic optical brightener portion of (P.sub.AB) to the total of cationic ammonium groups in the polycationic polymer (P.sub.A) portion of (P.sub.AB) is .gtoreq.80/100, and their aqueous compositions (W), their production and their use, also in combination with white pigments or fillers, in particular for the production of optically brightened paper.