Abstract: The present invention can sufficiently suppress curling phenomenon of a recorded product and facilitate handling of a printed product produced by using plain paper, in particular. The present invention provides a printing medium coating solution including water and a water-retentive, water-soluble organic compound, wherein the water-soluble organic compound includes only a water-soluble organic compound showing a difference of 36% or less between the water retention ability at a temperature of 23° C. and a humidity of 45% and the water retention ability at a temperature of 30° C. and a humidity of 80%; and the content of the water-soluble organic compound is 15 mass % or more with respect to the total amount of the printing medium coating solution.

Abstract: A reaction solution to be used for image recording with an ink containing a coloring material in a dissolved or dispersed state in order to achieve a high level of image density with stability, wherein the reaction solution contains a polyvalent metal ion and an organic solvent to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink, has a pH of 2 or higher, and has a buffering action for pH, wherein the buffering action means it can maintain pH variation within the range of 0.5 before and after the addition of 1.0 ml of a 0.1 N aqueous lithium hydroxide solution to 50 ml of the reaction solution.

Abstract: A reaction solution that is used for image recording with an ink containing a coloring material in a dissolved or dispersed state to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink to provide high quality and abrasion-resistant images, wherein the reaction solution contains at least a polyvalent metal ion and a nonionic polymer, the Ka value according to the Bristow method is from 1.3 mL·m?2·msec?1/2 to 3.0 mL·m?2·msec?1/2 inclusive, and the viscosity is from 20 mPa·s to 150 mPa·s inclusive.

Abstract: A reaction solution to be used for image recording with an ink containing a coloring material in a dissolved or dispersed state in order to achieve a high level of image density with stability, wherein the reaction solution contains a polyvalent metal ion and an organic solvent to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink, has a pH of 2 or higher, and has a buffering action for pH, wherein the buffering action means it can maintain pH variation within the range of 0.5 before and after the addition of 1.0 ml of a 0.1 N aqueous lithium hydroxide solution to 50 ml of the reaction solution.

Abstract: An ink set including a water-based ink containing a coloring material in a state dissolved or dispersed in an aqueous medium and a water-based reactive liquid containing a first component for insolubilizing or aggregating the coloring material in the ink by mixing with the water-based ink. The water-based reactive liquid contains a water-soluble high-molecular compound in a state dissolved therein. The water-based ink contains a second component, which is not insolubilized by the first component and the coloring material, in a state dissolved therein. The water-soluble high-molecular compound is not insolubilized by the first component and the coloring material but insolubilized by the second component.

Abstract: Provided is an ink-jet ink suitable for high speed printing and reduced ink ejection amount, wherein ink includes a water-insoluble coloring material dispersed in water with a resinous dispersant, glycerin, ethylene urea, and polyoxyethylene alkyl ether with HLB not lower than 13.

Abstract: An ink set comprises a water-based ink containing a coloring material in a state dissolved or dispersed in an aqueous medium and a water-based reactive liquid containing a first component for insolubilizing or aggregating the coloring material in the ink by mixing with the water-based ink. The water-based reactive liquid contains a water-soluble high-molecular compound in a state dissolved therein. The water-based ink contains a second component, which is not insolubilized by the first component and the coloring material, in a state dissolved therein. The water-soluble high-molecular compound is not insolubilized by the first component and the coloring material but insolubilized by the second component.

Abstract: A reaction solution that is used for image recording with an ink containing a coloring material in a dissolved or dispersed state to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink to provide high quality and abrasion-resistant images, wherein the reaction solution contains at least a polyvalent metal ion and a nonionic polymer, the Ka value according to the Bristow method is from 1.3 mL·m−2·msec−1/2 to 3.0 mL·m−2·msec−1/2 inclusive, and the viscosity is from 20 mPa·s to 150 mPa·s inclusive.

Abstract: A reaction solution to be used for image recording with an ink containing a coloring material in a dissolved or dispersed state in order to achieve a high level of image density with stability, wherein the reaction solution contains a polyvalent metal ion and an organic solvent to destabilize the dissolved or dispersed state of the coloring material in the ink in contact with the ink, has a pH of 2 or higher, and has a buffering action for pH, wherein the buffering action means it can maintain pH variation within the range of 0.5 before and after the addition of 1.0 ml of a 0.1 N aqueous lithium hydroxide solution to 50 ml of the reaction solution.

Abstract: Provided is an ink which comprises an aqueous medium and a coloring material dispersed in the aqueous medium with a dispersant, where the coloring material is contained in an amount of at most 1% by weight with respect to the total weight of the ink, and the ratio (B/P ratio) of the dispersant to the coloring material is larger than 1.

Abstract: Provided is an ink-jet ink suitable for high speed printing and reduced ink ejection amount, which ink comprise a water-insoluble coloring material dispersed in water with a resinous dispersant, glycerin, ethylene urea, and polyoxyethylene alkyl ether with HLB not lower than 13.

Abstract: Provided is an ink set including a plurality of inks each of which contains a water-insoluble coloring material and enabling ink-jet record images to be stably formed. The ink set includes first to nth aqueous inks for ink-jet recording, each of the aqueous inks containing a water-insoluble coloring material, an aqueous medium and a dispersant for dispersing the pigment in the aqueous medium, and a water-soluble organic compound, wherein the first to the nth aqueous inks are different from each other in pigment concentration based on the total weight of the each ink; and the first to the nth aqueous inks have the same or substantially the same viscosity at an actual usage temperature (T1).