Synthetic bilayer membranes are highly organized molecular aggregates and their characteristic organizations are maintained in aqueous dispersions as well as in their cast films. The interbilayer space of the cast film acts as extended two-dimensional matrices. Cocasting of aqueous bilayers and aqueous monomers/polymers can produce regular composite films. The subsequent polymerization/cross-linking and removal of the bilayer matrices lead to multilayered 2D-networks. Ion exchange combined with chemical treatments can produce ultrathin inorganic layers and well-defined inorganic clusters.