Abstract: A first ink composition includes: water; a water-soluble organic solvent; and a color developing agent. The color developing agent includes a pH indicator. The water-soluble organic solvent includes at least one water-soluble organic solvent having a SP value of 16 or less and 11 or more. An amount of the water-soluble organic solvent having a SP value of 16 or less and 11 or more in the first ink composition is 15 wt % or more. A second ink composition includes: water; a water-soluble organic solvent; and a color developing agent. The color developing agent includes a pH indicator. The water-soluble organic solvent includes at least one water-soluble organic solvent having a SP value of 16 or less. An amount of the water-soluble organic solvent having a SP value of 16 or less in the second ink composition is 15 wt % or more. The second ink composition is a water-based ink for ink-jet recording.

Abstract: A first ink composition includes: water; a water-soluble organic solvent; and a color developing agent. The color developing agent includes a pH indicator. The water-soluble organic solvent includes at least one water-soluble organic solvent having a SP value of 16 or less and 11 or more. An amount of the water-soluble organic solvent having a SP value of 16 or less and 11 or more in the first ink composition is 15 wt % or more. A second ink composition includes: water; a water-soluble organic solvent; and a color developing agent. The color developing agent includes a pH indicator. The water-soluble organic solvent includes at least one water-soluble organic solvent having a SP value of 16 or less. An amount of the water-soluble organic solvent having a SP value of 16 or less in the second ink composition is 15 wt % or more. The second ink composition is a water-based ink for ink-jet recording.

Abstract: An erasable ink set includes: an erasable ink; and an erasing time adjuster which is stored separately from the erasable ink and is capable of adjusting an erasing time of the erasable ink. The erasable ink includes a color developing agent including a pH indicator, water, and at least one selected from the group consisting of a first water-soluble organic solvent and a first surfactant. The erasing time adjuster includes water and at least one selected from the group consisting of a second water-soluble organic solvent and a second surfactant.

Abstract: A water-based ink for ink-jet recording includes dyes and water. The dyes include a blue dye having a hue angle of 220° to 280°; a yellow dye having a hue angle of 70° to 120°; and a copper phthalocyanine dye. A mass ratio (C/B) of a content (C) of the copper phthalocyanine dye to a content (B) of the blue dye in an entire amount of the water-based ink is equal to or more than 0.5, and a total content of the dyes in the entire amount of the water-based ink is equal to or more than 6% by mass.

Abstract: There is provided an ink set usable for forming an image on a recording medium which is fabric or recording paper, the ink set including: a water-based ink for ink-jet recording including a pigment, a first resin and water; and a treatment agent including a second resin and the water. The ink set satisfies the following conditions (1) to (3): condition (1): 0.9?(B+C)/A; condition (2): 3?A?9; condition (3): B<9. In the conditions (1) to (3), A: a blending amount (% by weight) of the pigment in an entire amount of the water-based ink; B: a blending amount (% by weight) of the first resin in the entire amount of the water-based ink; and C: a blending amount (% by weight) of the second resin in an entire amount of the treatment agent.

Abstract: There is provided a treatment agent applicable to a recording surface of a recording medium which is recording paper or fabric. The treatment agent contains: a non-cationic sizing agent; and at least one cationic substance which is selected from the group consisting of: a cationic polymer capable of forming a flexible film in a case that the cationic polymer is dried, a cationic surfactant, a polyvalent metal salt and a polyvalent metal ion.

Abstract: A water-based ink for ink-jet recording, includes: a solid solution of a quinacridone pigment including C.I. Pigment Violet 19 and C.I. Pigment Red 122, an azo pigment including C.I. Pigment Red 48:3, and water.

Abstract: A water-based ink for ink-jet recording includes: a solid solution of a quinacridone pigment including C.I. Pigment Violet 19 and C.I. Pigment Red 122; an azo pigment including C.I. Pigment Red 176; and water.

Abstract: A water-based ink for ink-jet recording includes: water; a solid solution pigment composed of at least a first pigment and a second pigment; and a non-solid solution pigment which is the same as the first pigment. An image L*60 of the first pigment has the highest chromaticness C* among those of pigments composing the solid solution pigment, the image L*60 having lightness L* which is closest to 60 among a plurality of solid images recorded on a recording paper by using one of aqueous dispersions containing the pigments composing the solid solution pigment at a same solid content concentration, respectively, while changing recording duty at every 5% in a range of 0% to 100%.

Abstract: A water-based ink for ink-jet recording includes: a solid solution of a quinacridone pigment including C.I. Pigment Red 202 and C.I. Pigment Violet 19; an azo pigment including C.I. Pigment Red 48:3; and water.

Abstract: A water-based ink for ink-jet recording, includes: a solid solution of a quinacridone pigment including C.I. Pigment Violet 19 and C.I. Pigment Red 202, an azo pigment including C.I. Pigment Red 150, and water.

Abstract: An image forming method uses an apparatus for forming an image on both recording media of fabric and recording paper. The image forming method includes: applying a treatment agent to the fabric, the treatment agent coagulating a water-based ink or increasing viscosity of the water-based ink; and discharging the water-based ink onto the fabric by an ink-jet system, the water-based ink being identical to a water-based ink used for forming the image on the recording paper.

Abstract: An image forming method uses an apparatus for forming an image on both recording media of fabric and recording paper. The image forming method includes: applying a treatment agent to the fabric, the treatment agent coagulating a water-based ink or increasing viscosity of the water-based ink; and discharging the water-based ink onto the fabric by an ink-jet system, the water-based ink being identical to a water-based ink used for forming the image on the recording paper.

Abstract: A water-based ink for ink-jet recording includes: a resin-dispersed pigment; an emulsion of a vinyl chloride-acrylic copolymer having a glass transition temperature of equal to or more than 50° C.; an anionic surfactant having only one anion group in a molecule thereof; and water. A ratio (S/E) of a blending amount (S) of the anionic surfactant to a solid content blending amount (E) of the emulsion of the vinyl chloride-acrylic copolymer in an entire amount of the water-based ink is equal to or more than 0.2.

Abstract: A water-based ink set for ink-jet recording includes: a water-based yellow ink containing water and a yellow dye having a blending amount in an entire amount of the water-based yellow ink of 2 to 3% by weight, the water-based yellow ink having a hue angle of 45° to 65°; a water-based magenta ink containing water and a magenta dye having a blending amount in an entire amount of the water-based magenta ink of 2 to 3% by weight, the water-based magenta ink having a hue angle of 340° to 360° or 0° to 5°; a water-based cyan ink containing water and a cyan dye having a blending amount in an entire amount of the water-based cyan ink of 2 to 3% by weight, the water-based cyan ink having a hue angle of 200° to 230°; and a water-based black ink containing water and a black dye having a blending amount in an entire amount of the water-based black ink of 6 to 7.5% by weight.

Abstract: There is provided a water-based ink for ink-jet recording including: water; a self-dispersible black pigment; and a resin-dispersed pigment of which hue angle is in a range of 180° to 270° and of which sedimentation velocity in the water-based ink is slower than sedimentation velocity of the self-dispersible black pigment in the water-based ink. A ratio (R/S) of a solid content weight (R) of the resin-dispersed pigment to a solid content weight (S) of the self-dispersible black pigment in the water-based ink is in a range of 0.26 to 0.80.

Abstract: There is provided a water-based ink for ink-jet recording including: water; a self dispersible black pigment of which mean particle diameter is not less than 140 nm; and a resin-dispersed pigment which is a copper phthalocyanine-based pigment and of which sedimentation velocity in the water-based ink is slower than sedimentation velocity of the self-dispersible black pigment in the water-based ink.

Abstract: An image forming method uses an apparatus for forming an image on both recording media of fabric and recording paper. The image forming method includes: applying a treatment agent to the fabric, the treatment agent coagulating a water-based ink or increasing viscosity of the water-based ink; and discharging the water-based ink onto the fabric by an ink-jet system, the water-based ink being identical to a water-based ink used for forming the image on the recording paper.

Abstract: There is provided an image forming method for forming an image on a recording medium which is fabric or recording paper by using an ink set including an ink and a treatment agent. In a case that the recording medium is the fabric, the image forming method includes: applying the treatment agent, which includes a cationic substance and a water-soluble organic solvent, to the fabric in an application amount of the treatment agent per an area of the fabric in a range of 4.7 mg/cm2 to 34 mg/cm2; drying the applied treatment agent and thereby reducing weight of the treatment agent in the fabric to be not more than 50% of the application amount of the treatment agent; and jetting the ink, which includes an anionic dye and a water-soluble organic solvent, onto the fabric by an ink-jet system.

Abstract: A water-based ink for ink-jet recording includes dyes and water. The dyes include a blue dye having a hue angle of 220° to 280°; a yellow dye having a hue angle of 70° to 120°; and a copper phthalocyanine dye. A mass ratio (C/B) of a content (C) of the copper phthalocyanine dye to a content (B) of the blue dye in an entire amount of the water-based ink is equal to or more than 0.5, and a total content of the dyes in the entire amount of the water-based ink is equal to or more than 6% by mass.