A composition comprises a solvent, and an electroconductive substance and
an amphiphilic block copolymers having a polyalkenyl ether repeating-unit
structure, or a block copolymer enclosing an electroconductive substance.
A black ink composition comprises a fine particulate metal having an
average particle diameter of not more than 20 nm, an amphiphilic block
copolymer, and a solvent. A method for forming an electroconductive
pattern by applying the composition. A method for forming an
electroconductive pattern by applying a composition comprises a block
copolymer enclosing an electroconductive substance, system to form an
electroconductive pattern on the substrate.