A micromagnetic study on antidot permalloy arrays is carried out in order to delimit their possibilities for high density storage. The dependence of the recorded bit quality on antidot size, separation distance, and film thickness is reported as well as hysteresis loops and coercivities. The simulations show a limit for the antidot size around 80 nm leading to maximum areal storage densities of about10 Gbits/in2.The results are interpreted in terms of demagnetizing, anisotropy, and exchange energies’ balance. ©1998 American Institute of Physics.