Abstract: The surface characteristics of polymeric materials are altered by exposure to a reactive gas which has been activated by radio frequency electromagnetic radiations prior to being directed onto the surface. The reactive gas is selected from either the gases which occur naturally with 3-electron bonds, (e.g., NO, NO.sub.2, etc,) or from other gases capable of decomposition in the presence of an electromagnetic field to form (1) activated species which attack the polymer surface to break carbon-hydrogen bonds, forming free radical sites, and (2) free radicals which react with these sites. The process can also be practiced using separate activator and reactive gases, and when the reactive gas selected comprises organic material, the gas stream used to treat the polymeric surface is supplemented by an activator gas comprising the noble gases and nitrogen.