To provide an ink for offset printing, which can be used for printing a thin paper with a small value, and also for obtaining high quality printed matter which can be obtained without the problem of striking through and deteriorating the appearance and the content to be informed.

The ink composition for printing is characterized by including 5-20 wt% of titanium oxide with the crystal form of rutile as a white pigment. The above ink composition is also characterized by that the average particle diameter of titanium oxide is 0.1-0.7 μm. The suitable printed matter is prepared by printing the above ink composition on a thin paper having a particular specification.