Methods and apparatus for producing a magnetic nanoparticle suitable for additive manufacturing techniques includes providing a solution having a plurality of metallic precursors to produce magnetic nanoparticles, a coordinating solvent, and a chelating agent. The solution is mixed and heated to grow nanoparticles wherein magnetic nanoparticles are formed. The solution is then cooled and a magnetic field is applied to the solution wherein ferrite nanoparticles are at least partially separated by size.

Methods and apparatus for producing a magnetic nanoparticle suitable for additive manufacturing techniques includes providing a solution having a plurality of metallic precursors to produce magnetic nanoparticles, a coordinating solvent, and a chelating agent. The solution is mixed and heated to grow nanoparticles wherein magnetic nanoparticles are formed. The solution is then cooled and a magnetic field is applied to the solution wherein ferrite nanoparticles are at least partially separated by size.

An image-recording method includes applying an ink to a recording medium and applying a liquid composition to the recording medium. The ink contains a pigment, and the liquid composition disturbs the dispersion state of the pigment in the ink. The applied liquid composition at least partially overlaps the area where the ink is applied. The ink contains a resin particle, a water-soluble resin, and at least one surfactant selected from fluorinated surfactants and silicone surfactants. The surfactant content of the ink is 2% by mass or more based on the total mass of the ink, and the mass ratio of the water-soluble resin content to the surfactant content of the ink is 0.3 or more and 3.0 or less.

An image-recording method includes applying an ink to a recording medium and applying a liquid composition to the recording medium. The ink contains a pigment, and the liquid composition disturbs the dispersion state of the pigment in the ink. The applied liquid composition at least partially overlaps the area where the ink is applied. The ink contains a resin particle, a water-soluble resin, and at least one surfactant selected from fluorinated surfactants and silicone surfactants. The surfactant content of the ink is 2% by mass or more based on the total mass of the ink, and the mass ratio of the water-soluble resin content to the surfactant content of the ink is 0.3 or more and 3.0 or less.

An aqueous resin particle dispersion, the resin comprises a repeating unit according to general formula (I). The resin particles can be incorporated in aqueous printing liquids such as aqueous inkjet inks.

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An aqueous inkjet ink comprises a compound functionalized with at least two functional groups selected from the group consisting of a primary amine and a secondary amine, a colorant and a polymeric particle comprising an oligomer or polymer having at least 3 repeating units comprising a functional group according to general formula I, II or III general formula I general formula II general formula III

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An aqueous inkjet ink comprises a compound functionalized with at least two functional groups selected from the group consisting of a primary amine and a secondary amine, a colorant and a polymeric particle comprising an oligomer or polymer having at least 3 repeating units comprising a functional group according to general formula I, II or III general formula I general formula II general formula III

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A cationic polymer nanoparticle, functionalized with primary amines, characterized in that said nanoparticle comprises a resin having at least a) a repeating unit selected from the group consisting of an allyl amine and a vinyl amine, b) an oxalyl amide crosslinking unit and c) a repeating unit according to general formula (I) and/or general formula (II); the particle can be dispersed in an aqueous vehicle to be used in inkjet printing.

A cationic polymer nanoparticle, functionalized with primary amines, characterized in that said nanoparticle comprises a resin having at least a) a repeating unit selected from the group consisting of an allyl amine and a vinyl amine, b) an oxalyl amide crosslinking unit and c) a repeating unit according to general formula (I) and/or general formula (II); the particle can be dispersed in an aqueous vehicle to be used in inkjet printing.

A printing method prints an image on a leather with an ink set including a color ink and a clear ink. The printing method includes: applying the clear ink to a region of the leather where the color ink is to be applied; applying the color ink onto the clear ink applied; and applying the clear ink onto the color ink applied.