The present disclosure relates to a method of treating a substrate comprising an elastomeric material, wherein the method comprises the steps of: a) providing a composition comprising: i. at least one fluoropolymer which is a copolymer comprising at least 90% by weight, based on the total weight of the copolymer, of units derived from tetrafluoroethene (TFE) and from one or more perfluorinated alkyl ethers corresponding to the general formula (I): Rf1—O—(CF2)n—CF═CF2 (I) wherein n is 1 or 0 and Rf1 represents a perfluoroalkyl residue which is optionally interrupted once or more than once by an oxygen atom; and ii. at least one solvent comprising a linear, cyclic or branched, partially fluorinated (poly)ether; b) contacting at least part of the substrate with the composition of step a); c) at least partially removing the at least one solvent; and d) optionally, when the fluoropolymer is curable, subjecting the fluoropolymer to curing, wherein the curing step may be carried out simultaneously with or after step c).