InSn seedlayers for Co/Pd multilayered media were engineered using dopants (Pd, O) to achieve grain size of 7.8±1.8 nm (σ=23%) and virgin magnetic cluster size of less than 65 nm. HN=-5 kOe and Hc=12.2 kOe make this media promising for extremely high-density recording. These parameters were all realized with room-temperature depositions without annealing. Media with O-doped 2-nm InSn seedlayers without other adhesion layers achieved Hc=6.2 kOe, which will be beneficial in reducing spacing loss. There is evidence that the engineered seedlayers also reduce the anisotropy dispersion and therefore the switching field distributions of these media.