A continuous jet printer includes a mixer (50) defining a first fluid inlet (51) for receiving a first fluid, a second fluid inlet (52) for receiving a second fluid, and a fluid outlet (53). The mixer mixes the first and second fluids to produce a printing fluid. A fluid source is in fluid communication with the inlets for delivering the fluids. A jet nozzle in fluid communication with the mixer delivers drops of the printing fluid to a substrate. The fluid source delivers the fluids to the inlets at an operating pressure of the jet nozzle. A method of printing includes mixing the fluids at an operating pressure of the jet nozzle to produce a printing fluid. The printing fluid is delivered to an inlet of the jet nozzle at the operating pressure of the jet nozzle, and a substrate is printed with drops of the printing fluid exiting the jet nozzle.