An ink set for ink-jet recording includes an achromatic color ink containing potassium ion and at least one of lithium ion and sodium ion; and a chromatic color ink containing at least one selected from the group consisting of: the potassium ion, the lithium ion and the sodium ion, wherein the ink set satisfies Condition (X): K.sub.a/(Li.sub.a+Na.sub.a+K.sub.a)>0.7, and Condition (Y): K.sub.c/(Li.sub.c+Na.sub.c+K.sub.c)<0.6.

An ink set for ink-jet recording includes an achromatic color ink containing potassium ion and at least one of lithium ion and sodium ion; and a chromatic color ink containing at least one selected from the group consisting of: the potassium ion, the lithium ion and the sodium ion, wherein the ink set satisfies Condition (X): K.sub.a/(Li.sub.a+Na.sub.a+K.sub.a)>0.7, and Condition (Y): K.sub.c/(Li.sub.c+Na.sub.c+K.sub.c)<0.6.

A multi-fluid kit for three-dimensional printing can include a wetting agent and a binding agent. The wetting agent can include from 0 wt % to about 49.8 wt % water, from about 0.5 wt % to about 30 wt % film-forming organic solvent that can have a boiling point from greater than about 100° C. to about 350° C., and from about 30 wt % to about 99.5 wt % amphiphilic solvent that can have a boiling point from about 45° C. to less than about 100° C. The amphiphilic solvent can be water-miscible and can be present in the wetting agent at a greater concentration than the water and at a greater concentration than the film-forming solvent. The binding agent can include from about 2 wt % to about 30 wt % of a polymer binder dispersed in an aqueous liquid vehicle.

A multi-fluid kit for three-dimensional printing can include a wetting agent and a binding agent. The wetting agent can include from 0 wt % to about 49.8 wt % water, from about 0.5 wt % to about 30 wt % film-forming organic solvent that can have a boiling point from greater than about 100° C. to about 350° C., and from about 30 wt % to about 99.5 wt % amphiphilic solvent that can have a boiling point from about 45° C. to less than about 100° C. The amphiphilic solvent can be water-miscible and can be present in the wetting agent at a greater concentration than the water and at a greater concentration than the film-forming solvent. The binding agent can include from about 2 wt % to about 30 wt % of a polymer binder dispersed in an aqueous liquid vehicle.

A three-dimensional printing kit can include a powder bed material and a fusing agent to selectively apply to the powder bed material. The powder bed material can include polymer particles and a thermochromic additive. The thermochromic additive can be chemically stable at a melting point temperature of the polymer particles, and the thermochromic additive can exhibit a color change at a color transition temperature that is below the melting point of the polymer particles. The fusing agent can include water and a radiation absorber to absorb radiation energy and convert the radiation energy to heat.

A three-dimensional printing kit can include a powder bed material and a fusing agent to selectively apply to the powder bed material. The powder bed material can include polymer particles and a thermochromic additive. The thermochromic additive can be chemically stable at a melting point temperature of the polymer particles, and the thermochromic additive can exhibit a color change at a color transition temperature that is below the melting point of the polymer particles. The fusing agent can include water and a radiation absorber to absorb radiation energy and convert the radiation energy to heat.

Provided are an active energy ray-curable ink including a photopolymerization initiator including a compound represented by Formula (1) and at least one of a monomer A composed of a photopolymerizable monomer having a molecular weight of 400 or more or a monomer B composed of a photopolymerizable monomer having a molecular weight of 130 or more and less than 400, and an image recording method. L.sup.1 represents an organic group having 20 or less carbon atoms and a valence of n, and n represents an integer of 3 to 8. AO represents an alkyleneoxy group having 2 or 3 carbon atoms, and m represents an integer of 0 to 15. L.sup.2 represents a single bond, an oxygen atom, a sulfur atom, or —NR.sup.11—. R.sup.11 represents a substituent. X represents an oxygen atom or a sulfur atom, and n R.sup.1's and n R.sup.2's each independently represent a substituent.

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A radiation curable liquid includes at least one free radical polymerizable monomer or oligomer, at least one diffusion hindered acetalyzation catalyst, and at least one diffusion hindered hydroxyl containing compound. The radiation curable liquid applied to a substrate prevents migration of very low viscous monomers, such as vinyl ether acrylate monomers, into the substrate.

A radiation curable liquid includes at least one free radical polymerizable monomer or oligomer, at least one diffusion hindered acetalyzation catalyst, and at least one diffusion hindered hydroxyl containing compound. The radiation curable liquid applied to a substrate prevents migration of very low viscous monomers, such as vinyl ether acrylate monomers, into the substrate.

An ink disclosed herein comprises a carrier liquid with a dispersion of flakes derived from a layered material. The thickness of each flake depends on the number of layers of the layered material in the flake. The thickness distribution of the flakes includes: at least 20% by number of single layer flakes; at least 40% by number cumulatively of single, double and triple layer flakes; or not more than 40% by number of flakes having ten or more layers. The layered material is selected from one or more of elemental materials such as graphene (typically derived from pristine graphite), metals (e.g., NiTe2, VSe2), semi-metals (e.g., WTa.sub.2, TcS.sub.2), semiconductors (e.g., WS.sub.2, WSe.sub.2, MoS.sub.2, MoTe.sub.2, TaS.sub.2, RhTe.sub.2, PdTe.sub.2), insulators (e.g., h-BN, HfS.sub.2), superconductors (e.g., NbS.sub.2, NbSe.sub.2, NbTe.sub.2, TaSe.sub.2) and topological insulators and thermo-electrics (e.g., Bi.sub.2Se.sub.3, Bi.sub.2Te.sub.3). Also disclosed are methods of manufacturing suitable inks and uses of the inks.