Abstract: The invention relates to a multilayer film including a substrate film, a biopolymer-based gas and/or water vapor barrier coating and optionally additional layers such as metal or metal oxide barrier layers and so-called primers that is applied to any one film layer to promote the adhesion another film layer or to printing inks, that can be used for many different applications, in particular the food and biomedical fields.

Abstract: The invention concerns lake compositions based on natural macromolecules (gelatin, chitosan, pectine etc.) with possible additions of vinyl polymers, metal-alcoxides etc., characterized by a barrier effect modulated in situ, in particular as a function of the relative humidity in the exterior ambient.