The application of functionally graded materials with spatial distribution of dielectric properties (d-FGM) can be an effective solution in reducing the electric field stress within an insulation system. In this work, the d-FGM material was synthesized using lamination method and half-curing process. The lamination is made up silicone rubber as the host matrix and nano-sized ZnO and a mixture of nano-sized ZnO and BaTiO3 with optimized permittivity and conductivity properties. Both simulation and experimental results shows an improvement in the electric field enhancement by using d-FGM.