Nanocomposites of natural rubber latex and layered silicates are prepared by a mild dispersion shear blending process. The results of X-ray diffraction (XRD) and transmission electron microscopy (TEM) show that clay particles are well dispersed in the dry latex and the platelets have a preferential orientation, forming translucent nanocomposites. These show tensile mechanical properties analogous to those obtained with vulcanized rubber as well as an increased solvent resistance, which is expected considering that there is significant adhesion between clay lamellae and rubber. Nanocomposite swelling is strongly anisotropic. Natural rubber properties may thus be strongly modified by nanocomposite formation producing unprecedented combinations of properties. (c) 2005 Elsevier Ltd. All rights reserved.