An ink-printed substrate includes a substrate and water-based ink composition printed on the substrate, and has a Crockfastness-Loss-to-Density Ratio of about 1.0 to about 6.0.

The magnetic recording medium has a nonmagnetic layer satisfying: the ratio of the total area accounted for by voids observed to the area of the observed region falls within a range of 13.0% to 25.0% in a sectional image taken by SEM; R+r is 58.0 nm or less and Rr is 21.0 nm or greater when denoting the average value of the diameters of corresponding circles for voids observed in the sectional image as R, denoting the standard deviation of the diameters of the corresponding circles as r; N+n is 185 voids/m.sup.2 or less and Nn is 120 voids/m.sup.2 or greater when denoting the average number of voids observed per m.sup.2 unit area of the observed region in the sectional image as N, denoting the standard deviation of this number as n; and the thickness of the nonmagnetic layer is 0.20 m or greater.

A perpendicular magnetic recording medium is disclosed in which crystal axis orientation dispersion, crystal grain diameter, and crystal grain diameter dispersion in a magnetic recording layer are reduced. The perpendicular magnetic recording medium has a structure having, stacked sequentially on a non-magnetic substrate, at least an amorphous underlayer, a lower orientation control layer made of Ru or Ru alloy of an hcp structure, an upper orientation control layer that is made of alloy containing an element selected from the group consisting of Co and Ni and an element selected from the group consisting of Cr, W, and Mo and that has an fcc or hcp structure, an intermediate layer, and a magnetic recording layer.

The magnetic recording medium has a nonmagnetic layer satisfying: the ratio of the total area accounted for by voids observed to the area of the observed region falls within a range of 13.0% to 25.0% in a sectional image taken by SEM; R+r is 58.0 nm or less and Rr is 21.0 nm or greater when denoting the average value of the diameters of corresponding circles for voids observed in the sectional image as R, denoting the standard deviation of the diameters of the corresponding circles as r; N+n is 185 voids/m.sup.2 or less and Nn is 120 voids/m.sup.2 or greater when denoting the average number of voids observed per m.sup.2 unit area of the observed region in the sectional image as N, denoting the standard deviation of this number as n; and the thickness of the nonmagnetic layer is 0.20 m or greater.