the invention concerns composites with excellent barrier properties to gases and water vapor . such composites can be used , e . g ., in foodstuff packaging or as technical membranes . the outstanding barrier effect is achieved by arranging on a substrate material , which , for example , may consist of biodegradable polymers , at least two films . at least one of these films consists of an organic - inorganic hybrid polymer , at least one further film of a further barrier material or of a substrate material .