Abstract: The invention concerns a composition for providing a substrate, after said substrate has been coated, with barrier properties to oils and greases, and complementarily to water. The invention is characterised in that it is obtainable by dispersion, at a temperature ranging between room temperature and about 70° C., of at least a film-forming gum or resin, not water-soluble and solubilized in at least a water-miscible solvent, in an aqueous solution containing at least a water soluble and lipophobic film-forming compound selected among proteins, polysaccharides and their mixtures, said composition having a temperature ranging between room temperature and about 70° C. The invention also concerns a method for preparing said composition, kits containing same, and a method for providing a substrate with barrier properties, and their uses, in particular for making packages and particularly packages for foodstuff.