To provide a printing ink for a printed matter accompanying an optical recording medium that does not cause deterioration of a polycarbonate substrate of the optical recording medium even when the printed surface of the accompanying printed matter directly contacts the substrate of the optical recording medium or even when the accompanying printed matter is stored for a long period of time together with the optical recording medium in an accommodating case for the optical recording medium.

The printing ink is an offset ink for a printed matter accompanying an optical recording medium, which does not contain an amine substance. The printed matter accompanying the optical recording medium is obtained by using the printing ink. A method for preventing the deterioration of a polycarbonate substrate of the optical recording medium comprises accommodating a printed matter obtained by printing on a paper substrate with use of the printing ink containing no amine substance together with the optical recording medium in an accommodating case for the optical recording medium.