A water base ink for ink-jet recording contains self-dispersible carbon
black as a coloring agent. The total content of an organic acid having a
number of carbon or carbons of 1 to 6 and a salt of the organic acid is
not more than 400 ppm. The organic acid having a number of carbon or
carbons of 1 to 6 includes monocarboxylic acid, dicarboxylic acid and oxy
acid, and the salt of the organic acid includes salts of these acids.
When the water base ink is used in an ink-jet recording apparatus, the
discharge stability of the ink is improved.