a material that will provide the desired resistance to penetration and migration of the vinyl plastisol coating as well as resistance to penetration of the wallpaper adhesive used to adhere the vinyl wallcover during application thereof to a suitable wall structure in the preferred embodiment the desired penetration resistance is achieved by utilizing a fluoro chemical treating agent commercially available in this connection it has been found that excellent results are obtained by using solutions and emulsions of metal complexed fluorinated salts and fluorinated polymeric treating agents that have been used commercially for resisting the penetration of aqueous fluids one such material that has been found particularly useful for the laminating backing is the 34 scotch ban 34 brand fluorochemical treating agent sold under the designation 34 fc 824 34 by minnesota mining and manufacturing this resin emulsion penetration inhibitor typically may be combined with antistatic agents extenders such as supplementary water repellent agents buffers and the like and conventionally is applied by passing the dried binder containing nonwoven fibrous web material through an aqueous emulsion of the penetration inhibitor and subsequently subjecting the treated sheet to a drying operation a typical aqueous emulsion treating formulation would contain about 0 7 to 1 5 parts by volume and preferably 1 25 parts by volume of fc 824 concentrate as received from the supplier with each 100 parts of water and would be used at a treating bath temperature of about 120 u00b0 to 150 u00b0 f other fluoro chemical materials having similar characteristics include metal complex solutions such as fc 805 a solution of a chromium complex of n ethyl n heptadecylfluoro octane sulfonyl glycine these are employed particularly on coating backing sheets other fluid repellant agents such as waxes silicones urethanes sizing.