Patent ID: 8586647

Claim:
A recording ink set comprising: a black ink, a cyan ink, a magenta ink, and a yellow ink, each of which comprises water, a water-insoluble color material, a water-soluble organic solvent, and a surfactant, wherein the black ink and at least one of the inks other than the black ink each comprise a different water-soluble organic solvent; and the surface tension of all the water-soluble organic solvent(s) used only for the inks other than the black ink is higher than that of the water-soluble organic solvent used only for the black ink, wherein the contact angle between a 2 μL ink drop and a recording medium, when measured 100 ms after the drop of each ink of the recording ink set is dropped on the recording medium, is 15 degrees to 35 degrees, and the recording medium is provided with a coating layer on at least one surface of a support and has a transfer amount of pure water to the recording medium, measured by the use of a dynamic scanning absorptometer, for a contact time of 100 ms being 3 mL/m 2 to 15 mL/m 2 .