An apparatus for conditioning ink, comprising: a body comprising: a chamber defined therein, an inlet port extending into the chamber for receiving ink from an ink supply station, a print head; an outlet port extending from the chamber for transporting ink from the chamber to the print head; and an ultrasonication mechanism comprising an energy source extending into the chamber for delivering ultrasonic energy to the ink within the chamber and further comprising an ultrasonic probe assembly, wherein the ultrasonic probe assembly comprises a vent having a gas outlet port, through which gas released though degassing is vented, wherein the vent and corresponding gas outlet port are located at an upper region of the chamber, such that gasses are vented without loss of ink; ink which comprises metallic particles; and a controller to control a power signal to the energy source (100, 134) to set a level of applied ultrasonic energy in magnitude or time, to produce different ink characteristics including color; wherein the energy provided by the energy source is in a frequency range of 20kHz to 400kHz to break down the metallic particles in the ink; wherein the ultrasonication mechanism is configured to reduce the size of the metallic particles before delivery of the conditioned ink to the print head, and wherein the print head is configured to deliver the conditioned ink having the reduced metallic particles onto a work piece. a body comprising: a chamber defined therein, an inlet port extending into the chamber for receiving ink from an ink supply station, a print head; an outlet port extending from the chamber for transporting ink from the chamber to the print head; and an ultrasonication mechanism comprising an energy source extending into the chamber for delivering ultrasonic energy to the ink within the chamber and further comprising an ultrasonic probe assembly, wherein the ultrasonic probe assembly comprises a vent having a gas outlet port, through which gas released though degassing is vented, wherein the vent and corresponding gas outlet port are located at an upper region of the chamber, such that gasses are vented without loss of ink; a chamber defined therein, an inlet port extending into the chamber for receiving ink from an ink supply station, a print head; an outlet port extending from the chamber for transporting ink from the chamber to the print head; and an ultrasonication mechanism comprising an energy source extending into the chamber for delivering ultrasonic energy to the ink within the chamber and further comprising an ultrasonic probe assembly, wherein the ultrasonic probe assembly comprises a vent having a gas outlet port, through which gas released though degassing is vented, wherein the vent and corresponding gas outlet port are located at an upper region of the chamber, such that gasses are vented without loss of ink; ink which comprises metallic particles; and a controller to control a power signal to the energy source (100, 134) to set a level of applied ultrasonic energy in magnitude or time, to produce different ink characteristics including color; wherein the energy provided by the energy source is in a frequency range of 20kHz to 400kHz to break down the metallic particles in the ink; wherein the ultrasonication mechanism is configured to reduce the size of the metallic particles before delivery of the conditioned ink to the print head, and wherein the print head is configured to deliver the conditioned ink having the reduced metallic particles onto a work piece.