PURPOSE: A writing ink composition that is prepared by adding a low-molecular water-soluble metallic compound and a water-soluble macromolecular compound as well as pigments and dyes to an aqueous medium, thus being erasable with commercially availabe erasers, when letters are written with this ink.

CONSTITUTION: The objective ink composition is obtained by adding (A) a low- molecular, water-soluble metallic compound such as alkali metal, alkaline earth metal, Zn, Cr, Mn chloride, nitrate or carboxylate, preferably by 10W50wt%, (B) a water-soluble macromolecular compound such as starch, polyvinyl alcohol, sodium polyacrylate or polymethacrylate, preferably a compound containing metallic salt, preferably by 0.1W8wt%, (C) a pigment or dye, preferably by 0.1W 15wt%, and when needed, (D) glycerol, preferably 3W40wt% to an aqueous medium.

USE: A writing ink for signature pen, ball point pen or fountain pen.