A method of producing an emissive toner composition including selecting a photoluminescent agent, a charge control agent, and one or more additives and combining the photoluminescent agent, charge control agent, and one or more additives to form an emissive toner composition that when printed to produce an image component on a substrate, the emission spectra of the image component for irradiation with a first excitation energy includes only dominant emission peaks corresponding to one or more dominant emission peaks of the photoluminescent agent. The photoluminescent agent is selected such that it emits light having one or more dominant emission peaks in a first emission spectral region when irradiated with the first excitation energy. The charge control agent and one or more additives are selected such that they do not emit light in the visible spectrum when irradiated with visible light and does not emit light in the first emission spectral region when irradiated with the first excitation energy.

A method of manufacturing a liquid electrophotographic ink includes: mixing a pigment with a resin powder; and microfluidizing the mixture together with a carrier fluid in a microfluidizer in a number of passes to form a concentrated ink containing composite particles.

A method of manufacturing a liquid electrophotographic ink includes: mixing a pigment with a resin powder; and microfluidizing the mixture together with a carrier fluid in a microfluidizer in a number of passes to form a concentrated ink containing composite particles.

Described herein is a liquid electrophotographic printing process comprising heating a coating composition comprising a thermoplastic polymer and a liquid carrier to dissolve the thermoplastic polymer in the liquid carrier and form a heated coating solution; and applying the heated coating solution to a liquid electrophotographically printed layer disposed on a substrate. The thermoplastic polymer may be selected from a copolymer of ethylene and an alk-1-ene and a copolymer of ethylene and 50 wt. % or less vinyl acetate; and the liquid carrier may comprise a hydrocarbon, a silicone oil or a vegetable oil. Also described herein are a liquid electrophotographic printing kit comprising a liquid electrophotographic ink composition and a coating composition, as well as a liquid electrophotographic printer.

Described herein is a liquid electrophotographic printing process comprising heating a coating composition comprising a thermoplastic polymer and a liquid carrier to dissolve the thermoplastic polymer in the liquid carrier and form a heated coating solution; and applying the heated coating solution to a liquid electrophotographically printed layer disposed on a substrate. The thermoplastic polymer may be selected from a copolymer of ethylene and an alk-1-ene and a copolymer of ethylene and 50 wt. % or less vinyl acetate; and the liquid carrier may comprise a hydrocarbon, a silicone oil or a vegetable oil. Also described herein are a liquid electrophotographic printing kit comprising a liquid electrophotographic ink composition and a coating composition, as well as a liquid electrophotographic printer.

According to an example, a mixing device comprises a first chamber including a solute addition member and a first mixer, a second chamber including a second mixer, a printing fluid pump, and a controller operatively connected to the solute addition member, the pump, the first mixer, and the second mixer. The controller is to control the pump to move printing fluid towards the printing fluid tank based on a printing fluid density level in the printing fluid tank, to control the solute addition member to add solids based on the printing fluid density level, and to control the first mixer and the second mixer to mix the added solids with the printing fluid moved by the pump.

According to an example, a mixing device comprises a first chamber including a solute addition member and a first mixer, a second chamber including a second mixer, a printing fluid pump, and a controller operatively connected to the solute addition member, the pump, the first mixer, and the second mixer. The controller is to control the pump to move printing fluid towards the printing fluid tank based on a printing fluid density level in the printing fluid tank, to control the solute addition member to add solids based on the printing fluid density level, and to control the first mixer and the second mixer to mix the added solids with the printing fluid moved by the pump.