The invention relates to a method for applying a cosmetic composition to hair. The method comprises the steps of removing a cosmetic composition from a sealed container, the composition comprising: a post-foaming emulsion comprising a weak acid, a weak base, a fatty acid, and a volatile buffering agent a film forming agent and an aqueous carrier applying said composition to one or more eyelashes and during or after said application to said one or more eyelashes, said cosmetic composition forms a foam, said foam resulting from the release of a gas, said gas being a reaction product of said post-foaming emulsion, and said reaction commencing after the evaporation of said volatile buffering agent, upon exposure of said cosmetic composition to atmospheric conditions.
