A general approach for the preparation of robust nanoscale inorganic layers on polymer film substrates is presented. Poly(tetrafluoroethylene-co-hexafluoropropylene), poly(4-methyl-1-pentene), and poly(ethylene terephthalate) were "activated" by the spontaneous adsorption of poly(vinyl alcohol); silica and titania were subsequently condensed on these surfaces by sequential vapor phase reaction with either silicon tetrachloride or titanium tetrachloride and water. The thickness and wettability of the inorganic layers can be controlled by the number of SiCl4 or TiCl4 and H2O reaction cycles. Reactions between the nanoscale inorganic layers and monochlorosilanes for silica and hydridosilanes for titania indicate that these surfaces have silica-like and titania-like reactivities.