Patent ID: 8399076

Claim:
An ink jet recording medium having an ink receiving layer containing a binder which contains an acrylonitrile butadiene copolymer, the butadiene concentration of the acrylonitrile butadiene copolymer is 50 weight % or more, and an inorganic pigment, wherein the ink receiving layer is on one or two sides of a base paper, wherein the base paper is mainly composed of wood pulp, wherein the concentration ratio of the acrylonitrile butadiene copolymer to 100 parts by weight of the inorganic pigment is from one part by weight to eight parts by weight, wherein the inorganic pigment consists of kaolin with particles having a particle size ranging from about 0.4 μm to about 4.2 μm which account for 64% or more as the cumulative value of the volumetric basis when measured using a laser diffraction method, and the surface roughness of the ink receiving layer is from 0.6 μm to 1.4 μm when a hard backing is used at a clamp pressure of 1,000 kPa according to JIS P8151.