A radically curable composition, especially a UV-Vis radiation radically curable printing ink, comprising (A) platelet-shaped transition metal particles, wherein the number mean diameter of the platelet-shaped transition metal particles, present in the composition, is in the range of from 15 nm to 1000 nm, as determined by the method defined in the description, the transition metal is selected from silver, copper, gold and palladium, especially silver and copper, very especially silver; (B) one, or more reactive diluents (B); (C) optionally one, or more oligomers (C); (D) one, or more photonitiators (D); (E) at least a surfactant (E), which is a block copolymer, comprising at least a block A and a block B, wherein a) the block A comprises a1) monomer units (A1) derived from a compound selected from alkyl (meth)acrylates, alkyl (meth)acrylamides, or any mixture thereof, and a2) monomer units (A2) derived from a hydroxy group, or ether group containing alkyl (meth)acrylate; b) the block B comprises monomer units (B) derived from a compound selected from fluorinated (meth)acrylic esters of formula H 2 C=CR 46 (C(O)OR F-1 ) (XX), wherein R 46 is H, or a methyl group; and R F-1 is an organic residue containing a perfluorinated alkyl group; (F) optionally one, or more polymeric binders; and (G) optionally one, or more solvents; (H) optionally further additives. (A) platelet-shaped transition metal particles, wherein the number mean diameter of the platelet-shaped transition metal particles, present in the composition, is in the range of from 15 nm to 1000 nm, as determined by the method defined in the description, the transition metal is selected from silver, copper, gold and palladium, especially silver and copper, very especially silver; (B) one, or more reactive diluents (B); (C) optionally one, or more oligomers (C); (D) one, or more photonitiators (D); (E) at least a surfactant (E), which is a block copolymer, comprising at least a block A and a block B, wherein a) the block A comprises a1) monomer units (A1) derived from a compound selected from alkyl (meth)acrylates, alkyl (meth)acrylamides, or any mixture thereof, and a2) monomer units (A2) derived from a hydroxy group, or ether group containing alkyl (meth)acrylate; b) the block B comprises monomer units (B) derived from a compound selected from fluorinated (meth)acrylic esters of formula H 2 C=CR 46 (C(O)OR F-1 ) (XX), wherein R 46 is H, or a methyl group; and R F-1 is an organic residue containing a perfluorinated alkyl group; a) the block A comprises a1) monomer units (A1) derived from a compound selected from alkyl (meth)acrylates, alkyl (meth)acrylamides, or any mixture thereof, and a2) monomer units (A2) derived from a hydroxy group, or ether group containing alkyl (meth)acrylate; a1) monomer units (A1) derived from a compound selected from alkyl (meth)acrylates, alkyl (meth)acrylamides, or any mixture thereof, and a2) monomer units (A2) derived from a hydroxy group, or ether group containing alkyl (meth)acrylate; b) the block B comprises monomer units (B) derived from a compound selected from fluorinated (meth)acrylic esters of formula H 2 C=CR 46 (C(O)OR F-1 ) (XX), wherein R 46 is H, or a methyl group; and R F-1 is an organic residue containing a perfluorinated alkyl group; R 46 is H, or a methyl group; and R F-1 is an organic residue containing a perfluorinated alkyl group; (F) optionally one, or more polymeric binders; and (G) optionally one, or more solvents; (H) optionally further additives. <EOS>