Patterning techniques that rely on high-resolution elastomeric elements such as stamps, molds, and conformable photomasks are operationally simple methods for nanofabrication that may find applications in areas such as molecular and organic electronics. The resolution of these "soft" lithographic procedures is often limited by the mechanical properties of the elastomers. We introduce here a chemically modified poly(dimethylsiloxane) material that is designed and optimized specifically for soft lithography, particularly in the nanometer regime. We demonstrate its use for nanopatterning tasks that are challenging with the commercially available elastomers that have been used in the past.