The improvement in mechanical and barrier properties of polymers reinforced with flake, fiber and even spherical nanocomposites is well documented. This improvement is not generally predicted from larger reinforcements or by classical mechanical models. Explanation of these property enhancements is generally dispensed with by invoking the increased surface area of very small particles. Exploring the source of these surface improvements through size and energy modification can provide further insight. The importance of concentration, size, distribution and material compatibility, particularly in surface mechanical properties, and combined solvent resistance and mechanical properties, provide diverse avenues of investigation.