Ink set, ink-jet recording process, ink-jet recording apparatus, and method for alleviating formation of solid within common recovery-system unit

摘要

An ink set comprising a black ink and a color ink, suitable for an ink-jet recording apparatus comprising a common recovery system for a black ink-ejecting orifice and a color ink-ejecting orifice. The black ink comprises particles of self-dispersing carbon black having at least one anionic hydrophilic group at the surface thereof in an aqueous medium, and the pH of the color ink is higher than the pH of the black ink.