Recent work with multilayer nanocoatings composed of polyelectrolytes and clay has demonstrated the ability to prepare super gas barrier layers from water that rival inorganic CVD-based films (e.g., SiO x ). In an effort to reduce the number of layers required to achieve a very low oxygen transmission rate (OTR (<0.01 cc/m2·day·atm)) in these nanocoatings, buffered cationic chitosan (CH) and vermiculite clay (VMT) were deposited using layer-by-layer (LbL) assembly. Buffering the chitosan solution and its rinse with 50 mM Trizma base increased the thickness of these films by an order of magnitude. The OTR of a 1.6-μm-thick, six-bilayer film was 0.009 cc/m2·day·atm, making this the best gas barrier reported for such a small number of layers. This simple modification to the LbL process could likely be applied more universally to produce films with the desired properties much more quickly.