Abstract: To quench the fluorescence produced by anionic fluorescent brighteners use is made of virtually colorless, water-soluble cationic or amphoteric compounds which contain in the molecule at least one ammonium group, at least two aryl, arylene, hetaryl and/or hetarylene groups and at least one nitro group.

Abstract: Basic triphendioxazine dyestuffs of the formula ##STR1## wherein Q denotes the radical ##STR2## or hydrogen, R.sub.1 and R.sub.2, independently of each other, denote hydrogen, halogen, alkyl, aryl, alkoxy, aryloxy, CN, CONH.sub.2, CONH--alkyl, CON(alkyl).sub.2, CONH--aryl, COO--alkyl, NH--CO--alkyl or NH--CO--aryl andR.sub.3 and R.sub.4, independently of each other, each denote hydrogen or alkyl, orR.sub.3 and R.sub.4 are joined together into a ring,A denotes a divalent hydrocarbon radical which is optionally interrupted by oxygen or sulphur,R.sub.5 denotes a radical of a polyamine which can be protonated or quaternized,R.sub.6 is defined the same way as R.sub.5 or denotes NH.sub.2, NH--alkyl, N(alkyl).sub.