Influence of organic modifying agent of clay on dispersion, distribution, hybrid microstructure formation, and associated performance properties of epoxidized natural rubber-based composites was evaluated. Binary and ternary composites of carbon black (CB) and two organomodified layered silicates (i.e., nanomer I30E and Cloisite 30B) were prepared and characterized based on small angle X-ray scattering, transmission electron microscopy, hydrodynamic swelling, tensile measurement, and dynamic mechanical analyses. Greater extent of exfoliation and nanounit formation was noted in ternary composites containing nanomer I30E, which was reflected in higher interfacial roughness (ds = 2.82) and lower radius of gyration (Rg = 205 angstrom). Morphological observations suggested higher nanomer I30ECB interactions than that of Cloisite 30BCB. The interplatelet distance in Cloisite 30B (d = 1.83 nm) stacks was lower than that of nanomer I30E (d = 2.26 nm). These two factors jointly contributed in higher breakdown of nanomer I30E stacks by CB than that of Cloisite 30B stacks. Greater exfoliation and nanounit formation in I30ECB-filled nanocomposite was also reflected in increased degree of crosslinking (n = 20 x 105%), tensile modulus/strength, half height width of damping peak (20.3 degrees C), and filler effectiveness (C = 0.33). POLYM. ENG. SCI., 2013. (c) 2012 Society of Plastics Engineers