The disclosure relates generally to a method for fabricating a patterned medium. The method includes providing a substrate with an exterior layer under a lithographically patterned surface layer, the lithographically patterned surface layer comprising a first pattern in a first region and a second pattern in a second region, applying a first masking material over the first region, transferring the second pattern into the exterior layer in the second region, forming self-assembled block copolymer structures over the lithographically patterned surface layer, the self-assembled block copolymer structures aligning with the first pattern in the first region, applying a second masking material over the second region, transferring the polymer block pattern into the exterior layer in the first region, and etching the substrate according to the second pattern transferred to the exterior layer in the second region and the polymer block pattern transferred to the exterior layer in the first region.