A method of processing a multilayer film is provided. The method includes providing a substrate film having a substrate film first surface and a substrate film second surface. The method also includes providing a barrier layer adjacent to the substrate film second surface. The barrier layer has at least one opening allowing fluid communication between the substrate film and an outer surface of the barrier layer. Further, the method includes contacting the substrate film first surface with a first reactant and finally contacting the outer surface of the barrier layer with a second reactant, said second reactant being reactive with said first reactant. The method of contacting the substrate film first surface to the first reactant and contacting the outer surface of the barrier layer to the second reactant is carried out under conditions under which reaction between said first reactant and the second reactant results in a formation of a reaction layer.