Aqueous ink for ink-jet printing

An aqueous ink for ink-jet printing comprising an aqueous solution of a water-soluble dye and a water-soluble organic solvent, wherein

• (1) said water-soluble dye is a mixture of (a) a compound having the formula I and (b) a compound having the formula II, a compound having the formula III or a mixture of compounds having the formulas II and III ##STR5## wherein M is an alkali metal;
• the peak ratio of (a)/(b) of said water-soluble dye, measured by liquid chromatography, is in the range of 0.9 to 3.0, the total concentration of NaCl and Na.sub.2 SO.sub.4 contained in said water-soluble dye is 3.0 wt. % or less;
• and the concentration of Ca contained in said water-soluble dye is 120 ppm or less;
• (2) said water-soluble organic solvent is a mixture consisting essentially of (c) glycerin and (d) at least one glycol selected from the group consisting of ethylene glycol, diethylene glycol, triethylene glycol, tetraethylene glycol and plyethylene glycol having an average molecular weight in the range of from 200 to 400, the weight ratio of (c):(d) being in the range of 1:1 to 1:5, and the concentration of said water-soluble organic solvent in said aqueous ink is in the range of from 10 wt. % to 30 wt. %;
• and
• (3) the surface tension of said aqueous ink at least 50 dynes/cm.