Electrochemical treatment of poly(tetrafluoroethylene) (PTFE) surfaces has been effected in localized areas of typical dimension of the order of 200 mum, leading to small regions of increased surface free energy. These have been studied by considering the wetting triple lines of tricresyl phosphate in the vicinity. Good correlation between theoretical predictions and observations of the shapes of the wetting lines was obtained, not only in the outer regions and on the untreated material, but also in the inner, treated zones. A predicted transition from concavity to convexity of the wetting line shape was corroborated by observations. The "excess wettability" of the treated zones of PTFE decreased following intense light exposure. Excess wettability, as evaluated from experimental data, exceeded predictions, possibly due to nonrespect of Antonow's rule at the local scale.