Patterned magnetic recording media, in which data bits are stored in discrete single-domain magnetic particles, have been proposed for the next generation of recording media. To achieve high densities, features with periodicities on the order of 25 nm and below are required over large areas, which is a challenging task for any lithography process. Block copolymers (BCPs), which phase-separate into ordered periodic nanoscale structures, might provide a path to accomplish such patterning. In this article, we describe BCP lithography and show how the self-assembled patterns can be templated to make large-area arrays of nanoscale structures with long-range order.