The development of nanocomposites traces back to the mid-80s, when the Toyota group introduced Polyamide-clay nanocomposites with largely enhanced mechanical properties by the addition of just 5 % of organomodified clay. A lot of different other nanofillers were investigated since that time in order to optimize mechanical, electrical, barrier and flammability properties, including clay, graphene, carbon nanotubes and hydrotalcite like materials, often called Layered Double Hydroxides (LDH). In all cases the interaction between filler and matrix is a crucial parameter for the success of nanocomposite preparation. With some examples the successful design of nano-fillers will be shown to achieve a function integrated nanocomposite.