Atom-transfer radical polymerization (ATRP) of benzyl methacrylate (BzMA) at ambient temperature was applied to step and flash imprint lithography. This process involved the formation of patterned polymeric networks (top-down) and the grafting polymerization of BzMA from these networks (bottom-up) via ATRP. Confocal laser scanning microscope and scanning electron microscope were used to determine the change in line-to-line separation (width) resulting from poly BzMA brush. The increase in line width at 400 nm could be maximized given a reaction time of 2 h. (c) 2006 Wiley Periodicals, Inc.