Micrometer scale patterns of polymethylene film was prepared by selective formation of polymethylene on a gold surface patterned with an organothiol monolayer as the resist. The monolayer effectively retarded the gold-catalyzed polymerization reaction from diazomethane. The polymethylene film, in the thickness range of 300-400 Angstrom, in turn serves as a stable resist in preventing electrochemical polymerization of polyaniline on the covered area. Selective deposition was thus achieved to give interdigitated patterns of conducting and insulating polymer films.