High permittivity SrTiO3 for the realization of all-dielectric metamaterials operating at terahertz frequencies was fabricated. A comparison of different processing routes evidences that Spark Plasma Sintering is the most effective sintering process to yield high density ceramic with high permittivity. We compare this sintering process with two others. The elaborated samples are characterized in the low frequency and in the terahertz frequency ranges. Their relative permittivities are compared w...