Abstract: An aqueous ink jet ink composition according to an aspect of the present disclosure is an ink jet ink composition including a pigment, a sparingly water-soluble low-molecular-weight organic compound, and a nonionic water-soluble resin, in which the pigment is a self-dispersion pigment or a resin dispersion pigment dispersed by a dispersant resin, and the nonionic water-soluble resin has a weight-average molecular weight of 2000 or greater, and a content of the nonionic water-soluble resin is 1% by mass or less with respect to a total mass of the ink composition.

Abstract: A water-based treatment liquid is used for recording together with an ink jet ink which is a water-based ink composition, and the treatment liquid contains: a polyvalent metal salt; a resin selected from an acrylic-based resin and a maleic acid-based resin; and a compound selected from an organic acid and an organic amine. In the treatment liquid described above, a content of the resin with respect to a total mass of the treatment liquid is 1 percent by mass or less, and the treatment liquid has a pH of 5.5 to 7.5.

Abstract: An ink set includes an ink composition and a treatment liquid composition. Each of the ink composition and the treatment liquid composition is used for printing by being applied onto a printing medium by an ink jet method. The ink composition is a water-based composition containing a coloring material and a surfactant. The treatment liquid composition is a water-based composition containing a flocculant and a surfactant. Any one of the ink composition and the treatment liquid composition contains a nitrogen-containing solvent. Each of the surfactant contained in the ink composition and the surfactant contained in the treatment liquid composition includes a silicone surfactant whose 0.1 mass % aqueous solution has a surface tension of 32 mN/m or less. Any one of the surfactant contained in the ink composition and the surfactant contained in the treatment liquid composition includes a silicone surfactant whose 0.1 mass % solution in a nitrogen-containing solvent has a surface tension of 32 mN/m or less.

Abstract: A maintenance method for an ink jet recording apparatus that performs recording using an ink composition and a treatment liquid containing a coagulant, wherein the ink jet recording apparatus has an ink jet head for ejecting the ink composition, the method includes a wiping step of wiping a nozzle-forming surface of the ink jet head with a maintenance liquid and an absorbent wiping member, and the maintenance liquid contains water that constitutes 80% or more by mass of a total mass of the maintenance liquid.

Abstract: A water-based ink jet ink composition according to the present disclosure includes: a colorant; an amine; and a water-soluble low molecular weight organic compound and is used for recording on a non-absorbing recording medium or a low-absorbing recording medium. The water-soluble low molecular weight organic compound contains an alkylene glycol monoether (B) represented by general formula (1) having a standard boiling point of 210° C. or less and an alkanediol (A) having a standard boiling point of 210° C. or less at a mass ratio (B/A) of 0.2 to 0.9, a content of a water-soluble low molecular weight organic compound having a standard boiling point of 250° C. or less is 8 to 30 percent by mass with respect to a total mass of the ink composition, a water-soluble low molecular weight organic compound which is an alkane polyol having a standard boiling point of more than 250° C.

Abstract: A treatment liquid is a water-based treatment liquid and is used for a recording method of adhering a water-based ink jet ink composition containing a colorant and the treatment liquid to a recording medium. The treatment liquid contains: an organic acid; and at least one selected from an organic acid polyvalent metal salt and a cationic polymer, a content of the at least one selected from an organic acid polyvalent metal salt and a cationic polymer is 1 to 15 percent by mass with respect to a total mass of the treatment liquid, and the treatment liquid has a pH of 5.5 or more.

Abstract: An ink jet ink composition which is a water-based ink, includes: a colorant; a resin; a water-soluble low molecular weight organic compound A which is one of an amide, a sulfur-containing compound, and a cyclic ether and which satisfies the following condition (a) and condition (b); and a silicone-based surfactant which satisfies the following condition (c). The condition (a) is that a surface tension of an aqueous solution at a concentration of 10 percent by mass is 42 to 56 mN/m, the condition (b) is that a standard boiling point is 150° C. to 300° C., and the condition (c) is that a solubility in water at 20° C. is 1 percent by mass or less.

Abstract: An ink jet recording method includes a treatment liquid attachment step, in which a treatment liquid is attached to a recording medium, and an ink attachment step, in which a water-based ink composition is attached to the recording medium. An ink jet recording apparatus includes a recording medium support and a heating mechanism that heats the recording medium support. The ink attachment step is carried out with the recording medium supported and heated by the recording medium support. In the ink attachment step, the recording medium is heated so that a surface thereof reaches a maximum temperature of 28.0° C. or more and 45.0° C. or less. The ratio between absorbances A and B (A/B) is 0.5 or more and 0.95 or less, where absorbance A is that of a 0.1% by mass mixture of the water-based ink composition in the treatment liquid, and absorbance B is that of a 0.1% by mass mixture of the water-based ink composition in purified water.

Abstract: An ink set according to the present disclosure includes: a treatment liquid containing an aggregating agent; a deep ink composition; and a light ink composition, the ink compositions containing colorants, belonging to the same color system, and each being a water-based ink jet ink, the light ink composition contains an organic solvent which is a condensate of an alkanediol having 2 or 3 carbon atoms and which has two hydroxy groups, and the deep ink composition contains an organic solvent which is an alkanediol having 2 to 4 carbon atoms.

Abstract: An ink jet ink composition is a water-based ink that contains at least one pigment and at least one resin and is for use in recording on a low- or non-absorbent recording medium. The ink composition contains at least one water-soluble low-molecular-weight organic compound that has a melting point of 30° C. or above and is any of an amide, sulfur-containing compound, or cyclic ether, and the low-molecular-weight organic compound constitutes 10% by mass or less of the total mass of the ink composition. The ink composition also contains at least one organic solvent that is a diol having a melting point of 25° C. or below, and the organic solvent constitutes a higher percentage than the low-molecular-weight organic compound.

Abstract: A printing method for printing a printing medium includes a non-white ink application step of applying an aqueous non-white ink composition containing a non-white coloring material onto the printing medium, and a white ink application step of applying an aqueous white ink composition containing a white coloring material onto the non-white ink composition on the printing medium to form a superimposed region. The non-white ink composition and the white ink composition each have an organic solvent content limited to 15% or less relative to the total mass of the corresponding ink composition. The mass ratio of the white ink composition to the non-white ink composition in the superimposed region is 1.5 or more in a portion to which the non-white ink composition is applied in an amount largest in the superimposed region.

Abstract: A form of an ink set is an ink set including a flocculant-containing treatment liquid and an ink jet ink composition and is for use in recording on a low- or non-absorbent recording medium. The ink jet ink composition is a water-based ink containing at least one colorant, at least one water-soluble organic compound, having a solubility of more than 10 g in 100 g of water at 20° C., and at least one organic compound sparingly soluble in water, having a solubility of 0.1 to 10 g in 100 g of water at 20° C. The organic compound sparingly soluble in water includes a diol or glycol ether having a normal boiling point of 180° C. to 300° C., with the diol or glycol ether constituting 2.3% by mass or less of the total mass of the ink composition.

Abstract: A printing method for printing a printing medium whose printed side will be laminated after being printed. The printing method includes a non-white ink application step of applying an aqueous non-white ink composition containing a non-white coloring material onto the printing medium, a white ink application step of applying an aqueous white ink composition containing a white coloring material onto the non-white ink composition on the printing medium, and a clear ink application step of applying a clear ink composition containing a resin onto the white ink composition on the printing medium.

Abstract: An ink set includes a treatment liquid containing an aggregating agent and an ink composition, and the ink composition is a water-based ink containing a pigment dispersed by a pigment dispersant or a self-dispersible pigment; a water-dispersible resin; and a maleic acid-based resin which is a water-soluble resin.

Abstract: The ink jet printing method includes applying an aqueous coloring ink composition onto a printing surface of a printing medium by being ejected from an ink jet head. The printing surface of the printing medium contains natural fibers and synthetic fibers.

Abstract: An ink composition is used for recording on a low-absorbing recording medium or a non-absorbing recording medium and is an aqueous ink jet ink containing a pigment, and the ink composition includes 1.2 to 2.9 percent by mass of an amine with respect to a total mass of the ink composition, and an organic solvent other than an amine. The organic solvent includes an organic solvent having a standard boiling point of 150° C. to 250° C. in an amount of 5 to 30 percent by mass with respect to the total mass of the ink composition, and the organic solvent having a standard boiling point of 150° C. to 250° C. includes a diol having a water mixture viscosity of 3.0 mPa·s or more.

Abstract: An ink set includes an ink composition and a treatment liquid composition. Each of the ink composition and the treatment liquid composition is used for printing by being applied onto a printing medium by an ink jet method. The ink composition is a water-based composition containing a coloring material and a surfactant. The treatment liquid composition is a water-based composition containing a flocculant and a surfactant. Any one of the ink composition and the treatment liquid composition contains a nitrogen-containing solvent. Each of the surfactant contained in the ink composition and the surfactant contained in the treatment liquid composition includes a silicone surfactant whose 0.1 mass % aqueous solution has a surface tension of 32 mN/m or less. Any one of the surfactant contained in the ink composition and the surfactant contained in the treatment liquid composition includes a silicone surfactant whose 0.1 mass % solution in a nitrogen-containing solvent has a surface tension of 32 mN/m or less.

Abstract: An ink jet printing method includes scanning a printing medium in a scanning direction a plurality of times with an ink jet head from which inks and a treatment liquid acting to flocculate constituents of the inks are ejected. The ink jet head includes first ink nozzles filled with a first ink and arranged in a sub-scanning direction, second ink nozzles filled with a second ink having a different composition from the first ink and arranged in the sub-scanning direction, and treatment liquid nozzles filled with the treatment liquid and arranged in the sub-scanning direction. At least some of the treatment liquid nozzles are coincident in the sub-scanning direction with the first and second ink nozzles. The first ink nozzles are closest to the treatment liquid nozzles in the scanning direction, and the first ink exhibits a viscosity increase by a factor of 6.0 or less.

Abstract: A maintenance method for an ink jet recording apparatus that performs recording using an ink composition and a treatment liquid containing a coagulant, wherein the ink jet recording apparatus has an ink jet head for ejecting the ink composition, the method includes a wiping step of wiping a nozzle-forming surface of the ink jet head with a maintenance liquid and an absorbent wiping member, and the maintenance liquid contains water that constitutes 80% or more by mass of a total mass of the maintenance liquid.

Abstract: An ink jet recording method includes a treatment liquid attachment step, in which a treatment liquid is attached to a recording medium, and an ink attachment step, in which a water-based ink composition is attached to the recording medium. An ink jet recording apparatus includes a recording medium support and a heating mechanism that heats the recording medium support. The ink attachment step is carried out with the recording medium supported and heated by the recording medium support. In the ink attachment step, the recording medium is heated so that a surface thereof reaches a maximum temperature of 28.0° C. or more and 45.0° C. or less. The ratio between absorbances A and B (A/B) is 0.5 or more and 0.95 or less, where absorbance A is that of a 0.1% by mass mixture of the water-based ink composition in the treatment liquid, and absorbance B is that of a 0.1% by mass mixture of the water-based ink composition in purified water.