The nacreous layer of mollusk shells is both strong and stiff. This is attributed to the unique three-dimensional (3D) assembly of platelet-like ceramic building blocks which are embedded in a polymer matrix. Layer-by-layer (LBL) assembly of clay nanoplates and polyelectrolytes has been developed to make polymer nanocomposites that mimic the natural structures and mechanical properties of nacres. However, the LBL approach is a slow process that requires hours to assemble a micrometer-thick film. Here we report the rapid formation of large-area nacreous coatings by utilizing capillary, electrical, and shear forces. Hexagonal gibbsite nanoplates with ~200 nm diameter and ~10 nm thickness can be assembled into ordered multilayers with controlled thickness from submicrometer to hundreds of microns. The interstitials between gibbsite particles can be filled up by polymers and metals. The resulting nanocomposites exhibit notable stiffness and strength.