Ink set, ink-jet printing method using such ink set, recording unit, ink cartridge and ink-jet printing apparatus

An ink-jet recording method comprising steps of:

• (1) applying a first ink containing an aqueous medium and an anionic dye as coloring material onto a printing medium by an ink-jet method;
• (2) applying a second ink containing an aqueous medium and an anionic dye as coloring material and having a lower coloring material content than the first ink onto the printing medium by means of an ink-jet method;
• and
• (3) applying a third ink containing an aqueous medium, a first pigment, a second pigment and a polymeric dispersant for dispersing said second pigment, both said first pigment and said second pigment being contained in a dispersed state, onto the printing medium by an ink-jet method;
• said first pigment of self-dispersible pigment and having an anionic group bound to the surface directly or via another atomic group;
• said second pigment dispersible to said aqueous medium by means of said polymeric dispersant;
• said polymeric dispersant being at least either an anionic polymeric dispersant or a nonionic polymeric dispersant;
• said second ink further containing a substance which destabilizes the dispersion stability of at least either the first pigment or the second pigment in said third ink when the second ink is brought into contact with said third ink in a liquid state on the printing medium;
• said step (2) being carried out either subsequent to or practically simultaneously with said step (3) so as to make the second ink and the third ink contact each other in a liquid state on the printing medium.

An ink-jet recording method comprising steps of:

• (1) applying a first ink containing an aqueous medium and an anionic dye as coloring material onto a printing medium by an ink-jet method;
• (2) applying a second ink containing an aqueous medium and an anionic dye as coloring material and having a lower coloring material content than the first ink onto the printing medium by means of an ink-jet method;
• and
• (3) applying a third ink containing an aqueous medium, a first pigment, a second pigment and a polymeric dispersant for dispersing said second pigment, both said first pigment and said second pigment being contained in a dispersed state, onto the printing medium by an ink-jet method;
• said first pigment being a self-dispersible pigment having at least an anionic group bound to the surface directly or via another atomic group;
• said second pigment being dispersible to said aqueous medium by means of said polymeric dispersant;
• said polymeric dispersant being at least either an anionic polymeric dispersant or a nonionic polymeric dispersant;
• said second ink further containing a substance which destabilizes the dispersion stability of at least either the first pigment or the second pigment in said third ink when the second ink is brought into contact with said third ink in a liquid state on the printing medium;
• said step (3) being carried out either subsequent to or practically simultaneously with said step (2) so as to make the second ink and the third ink contact each other in a liquid state on the printing medium.