Cationic oligomeric dye of the formula wherein X 1 and X 2, independently from each other are a linkage group selected from C 1 -C 30 alkylene C 2 -C 12 alkenylene, C 5 -C 10 arylene, C 5 -C 10 cycloalkylene or C 1 -C 10 alkylene(C 5 -C 10 arylene) which may be interrupted and/or terminated at one or both ends by one or more than one -O-, -S-, -N=, -N(R 1)-, S -, -SO 2 -, -(CH 2 CH 2 -O) 1-5 -, -(CH 2 CH 2 CH 2 -O) 1-5 -, -C -, -C O-, -OC -, or -CON(R 1)-, -C(NR 1 R 2) 2 -, -(R 1)NC - -C R 1 - or an optionally substituted, saturated or unsaturated, fused or non-fused aromatic or non-aromatic (hetero)cyclic bivalent radical optionally comprising at least one heteroatom; -O-; -S-; -N(R 1)-; -S -; SO 2 -; -(CH 2 CH 2 -O) 1-5 -; -C -; -C O-, -OC -; -C N(R 1)-; S 2 N(R 1)-; -C(NR 1 R 2) 2 -; -(R 1)NC -; -C R 1 -; saturated or unsaturated, fused or non-fused aromatic or nonaromatic bivalent radical optionally comprising at least one heteroatom, which is optionally substituted by C 1 -C 30 alkyl, C 1 -C 30 alkoxy, C 2 -C 12 alkenyl, C 5 -C 10 aryl, C 5 -C 10 cycloalkyl, C 1 -C 10 alkyl(C 5 -C 10 arylene), halogen, hydroxy, E or E', or the direct bond; R 1 and R 2 independently from each other hydrogen; or unsubstituted or substituted, straight-chain or branched, monocyclic or polycyclic, interrupted or uninterrupted C 1 -C 14 alkyl; C 1 -C 14 hydroxyalkyl; C 1 -C 14 aminoalkyl; C 2 -C 14 alkenyl; C 6 -C 10 aryl; C 6 -C 10 aryl-CrC 10 alkyl; or C 5 -C 10 alkyl(C 5 -C 10 aryl); Y 1 and Y 2 are selected from the radical of formula wherein Hal is a halogen anion; An 1 and An 2 independently from each other are an anion; E and E' are hydrogen, X 1 Y 1 a+, X 2 Y 2 b+; or a nitrogen containing heterocyclic radical; a and b independently from each other are a number from 1 to 3; m is a number of 2 or 3; and n is a number from 3 to 6; wherein at least 90% of the polyamine molecules are selected from tetramines, pentamines and hexamines. X 1 and X 2, independently from each other are a linkage group selected from C 1 -C 30 alkylene C 2 -C 12 alkenylene, C 5 -C 10 arylene, C 5 -C 10 cycloalkylene or C 1 -C 10 alkylene(C 5 -C 10 arylene) which may be interrupted and/or terminated at one or both ends by one or more than one -O-, -S-, -N=, -N(R 1)-, S -, -SO 2 -, -(CH 2 CH 2 -O) 1-5 -, -(CH 2 CH 2 CH 2 -O) 1-5 -, -C -, -C O-, -OC -, or -CON(R 1)-, -C(NR 1 R 2) 2 -, -(R 1)NC - -C R 1 - or an optionally substituted, saturated or unsaturated, fused or non-fused aromatic or non-aromatic (hetero)cyclic bivalent radical optionally comprising at least one heteroatom; -O-; -S-; -N(R 1)-; -S -; SO 2 -; -(CH 2 CH 2 -O) 1-5 -; -C -; -C O-, -OC -; -C N(R 1)-; S 2 N(R 1)-; -C(NR 1 R 2) 2 -; -(R 1)NC -; -C R 1 -; saturated or unsaturated, fused or non-fused aromatic or nonaromatic bivalent radical optionally comprising at least one heteroatom, which is optionally substituted by C 1 -C 30 alkyl, C 1 -C 30 alkoxy, C 2 -C 12 alkenyl, C 5 -C 10 aryl, C 5 -C 10 cycloalkyl, C 1 -C 10 alkyl(C 5 -C 10 arylene), halogen, hydroxy, E or E', or the direct bond; R 1 and R 2 independently from each other hydrogen; or unsubstituted or substituted, straight-chain or branched, monocyclic or polycyclic, interrupted or uninterrupted C 1 -C 14 alkyl; C 1 -C 14 hydroxyalkyl; C 1 -C 14 aminoalkyl; C 2 -C 14 alkenyl; C 6 -C 10 aryl; C 6 -C 10 aryl-CrC 10 alkyl; or C 5 -C 10 alkyl(C 5 -C 10 aryl); Y 1 and Y 2 are selected from the radical of formula wherein Hal is a halogen anion; An 1 and An 2 independently from each other are an anion; E and E' are hydrogen, X 1 Y 1 a+, X 2 Y 2 b+; or a nitrogen containing heterocyclic radical; a and b independently from each other are a number from 1 to 3; m is a number of 2 or 3; and n is a number from 3 to 6;