PURPOSE: To realize the formation of a water-base radiation-curable magnetic paint by mixing a specified radiation-curable, water-soluble or self-emulsifiable resin, a radiation-curable resin or compound containing unsaturated double bonds, and a radiation-curable resin or compound containing sulfo groups or phosphate groups.

CONSTITUTION: A radiation-curable magnetic paint formed by dispersing a magnetic powder in an aqueous resin composition consisting of: a water-soluble or self-emulsifiable resin (A) containing radiation-curable double bonds and carboxyl groups partially or wholly neutralized with ammonia or an amine and having an average molecular weight of at least 2,000, wherein the carboxyl group content is such that the molecular weight for one carboxyl group is at most 400; a resin or compound (B) containing at least two radiation-curable unsaturated double bonds in the molecule and having an average molecular weight of below 2,000; and a resin or compound (C) containing radiation-curable unsaturated double bonds and a sulfo and/or phosphate group partially or wholly neutralized with ammonia or an amine and having a solubility in water at 20°C of at least 5wt.%.