Patent ID: 8025384

Claim:
A reaction liquid, used with an ink comprising carbon black as a coloring material and acetylene glycol ethylene oxide adduct as a surfactant, and destabilizing one of a dissolved state and dispersed state of the coloring material in the ink by being in contact with the ink on a recording medium, wherein the reaction liquid comprises: calcium ions; glycerin; polyethylene glycol having an average molecular weight of 200 or more and 1,000 or less; and acetylene glycol ethylene oxide adduct as a surfactant, wherein the content of the calcium ions, A (% by mass), is 2.7% by mass or more and 4.3% by mass or less, based on the total mass of the reaction liquid, wherein the sum total of the content of the glycerin, B (% by mass), and the content of the polyethylene glycol, C (% by mass), based on the total mass of the reaction liquid is 6 times or more and 11 times or less the content of the calcium ions A (% by mass), wherein the ratio of the content of the glycerin B (% by mass) to the sum total of the content of the glycerin B (% by mass) and the content of the polyethylene glycol C (% by mass), (B/(B+C)), is 0.3 or more and 0.7 or less, wherein the content of the surfactant in the reaction liquid is more than that in the ink, and wherein the content of the surfactant in the reaction liquid (% by mass) is 0.30% by mass or more and 0.80% by mass or less, based on the total mass of the reaction liquid.