Abstract: The object of the invention is to provide an oil ink set capable of obtaining images having high color reproduction capabilities and high color saturation in particular. The oil ink set of the invention comprises a firsts a second, and a third oil ink having a wavelength region in which the reflectivity of each oil ink on a recording medium changes from 80% to 5% in the wavelength range of 400 nm to 700 nm. In this wavelength region, the reflectivity of the first oil ink is continuously higher than that of the first oil ink, and in the wavelength in which the reflectivity of the second oil ink changes from 80% to 5%, the reflectivity of the third oil ink is continuously higher than that of the second oil ink. Moreover, the coloring materials in the first, the second and the third oil inks are all different.

Abstract: An oil-based ink composition for ink jet recording of the present invention contains a colorant and at least 50% by weight of a mixed solvent made by mixing from 0.02 to 4 parts by weight of a lactone-type solvent with 1 part by weight of polyoxyethylene glycol dialkyl ether represented by the following general formula (1): R11—(OC2H4)n—OR12??General Formula (1) (wherein R11, R12 represent alkyl groups having from 1 to 3 carbon atoms and can be the same or different, and n is an integer from 2 to 4). The oil-based ink composition can be suitably used for printing on a polyvinyl chloride substrate and is excellent in all of print quality, printing stability, dry characteristics of printed matter, and storage stability of ink.