This article describes an ink-jet printer for the construction of combinatorial libraries and functionally graded ceramics. It can mix and print all possible compositions for high-throughput screening. The number of components is set by the number of mixing valves that deliver ceramic ink from pressurized reservoirs into a circulation chamber. Compositional control is by either complete or incremental change. Organic liquids and ceramic inks are used in a systematic three-stage calibration. The calibration protocol accounts for the effects of ink viscosity, reservoir pressure, valve-opening time, and temperature, but reveals unexpected segregation effects that occur in the ink after deposition.