The use of a decal transfer lithography technique to fabricate elastomeric stamps with triangular cross-sections, specifically triangular prisms and cones, is described. These stamps are used in demonstrations for several prototypical optical applications, including the fabrication of multiheight 3D photoresist patterns with near zero-width features using near-field phase shift lithography, fabrication of periodic porous polymer structures by maskless proximity field nanopatterning, embossing thin-film antireflection coatings for improved device performance, and efficient fabrication of substrates for surface-enhanced Raman spectroscopic sensing. The applications illustrate the utility of the triangular poly(dimethylsiloxane) decals for a wide variety of optics-centric applications, particularly those that exploit the ability of the designed geometries and materials combinations to manipulate lightmatter interactions in a predictable and controllable manner.