To provide a method for improving light resistance of an energy beam-curable resin composition capable of being coated without using organic solvents having adverse effects on the human body and environment, imparting a cured film excellent in stability, curability, near-infrared absorbability, fluorescence properties and light resistance and capable of being used as a near- infrared absorbing ink and a fluorescence ink.

This method for improving the light resistance is characterized by previously installing (D) an energy beam-curable undercoat layer when coating the energy beam-curable resin composition comprising (A) a resin having an ethylenic unsaturated group in the molecule, (B) a compound absorbing near infrared rays within the range of 650-1,000 nm and (C) a light resistance improving agent.