Provided is an active energy ray curable-type ink comprising: scale-like metal particles; and polymerizable compounds, wherein the scale-like metal particles contain indium and have an average equivalent circle diameter of 50 nm to 1,000 nm and an average aspect ratio, which is a ratio of the average equivalent circle diameter to an average thickness, of 5 to 100.

A water-based ink jet ink composition according to the present disclosure includes: a colorant; an amine; and a water-soluble low molecular weight organic compound and is used for recording on a non-absorbing recording medium or a low-absorbing recording medium. The water-soluble low molecular weight organic compound contains an alkylene glycol monoether (B) represented by general formula (1) having a standard boiling point of 210° C. or less and an alkanediol (A) having a standard boiling point of 210° C. or less at a mass ratio (B/A) of 0.2 to 0.9, a content of a water-soluble low molecular weight organic compound having a standard boiling point of 250° C. or less is 8 to 30 percent by mass with respect to a total mass of the ink composition, a water-soluble low molecular weight organic compound which is an alkane polyol having a standard boiling point of more than 250° C. is not contained at a content of more than 3 percent by mass with respect to the total mass of the ink composition, and a content of the amine with respect to the total mass of the ink composition is 5 percent by mass or less.

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In the general formula (1), R.sub.1 represents an alkylene group having 2 to 5 carbon atoms, R.sub.2 represents an alkyl group having 1 or 2 carbon atoms, and n represents 1 or 2.

An ink contains an anionic compound, water, a photoacid generator, and one or more organic solvents containing at least one organic solvent having a solubility parameter of from 9 to 11.8 (J/cm.sup.3).sup.1/2.

An ink contains an anionic compound, water, a photoacid generator, and one or more organic solvents containing at least one organic solvent having a solubility parameter of from 9 to 11.8 (J/cm.sup.3).sup.1/2.

An ink jet ink composition contains a dye having an azo group, water, and a hindered amine compound having a radical. The dissolved nitrogen concentration of the ink composition is 10 ppm or less.

An ink jet ink composition contains a dye having an azo group, water, and a hindered amine compound having a radical. The dissolved nitrogen concentration of the ink composition is 10 ppm or less.

An inkjet printing process and an ink set for forming an image on a substrate by applying a plurality of inkjet inks of the ink set on the substrate. The plurality of inkjet inks include at least a first ink and a second ink, each ink comprising: a pigment and a block copolymer dispersant for dispersing the pigment. The block copolymer dispersant includes a first block and a second block where the second block is formed using at least one monomer M.sub.2, which monomer M.sub.2 is selected from the group consisting of a methacrylate and an acrylate, and where the monomer M.sub.2 is an anchoring monomer for anchoring to the pigment.

An inkjet printing process and an ink set for forming an image on a substrate by applying a plurality of inkjet inks of the ink set on the substrate. The plurality of inkjet inks include at least a first ink and a second ink, each ink comprising: a pigment and a block copolymer dispersant for dispersing the pigment. The block copolymer dispersant includes a first block and a second block where the second block is formed using at least one monomer M.sub.2, which monomer M.sub.2 is selected from the group consisting of a methacrylate and an acrylate, and where the monomer M.sub.2 is an anchoring monomer for anchoring to the pigment.

A cosmetic handy ink-jet printer including an ink-jet head for ejecting an ink containing an inorganic pigment, an ink circulation device for circulating the ink, and a body deelectrification device for removing static electricity from a body of the printer. The ink circulation device includes an ink receptacle in which the ink is accommodated, and an ink circulation path through which the ink is circulated. The body deelectrification device is a capacitor or a grounded circuit.

An object of the present invention is to provide a phycocyanin pigment composition insoluble in water and provide food, cosmetics, a coating material or a printing marker for pharmaceuticals or agricultural chemicals, a stationery product, a writing tool, a printing ink, an inkjet ink, a metal ink, a paint, a plastic coloring agent, a color toner, a fluorescent labeling agent, a fluorescent probe, or a chemical sensor, each containing the pigment composition. It was found that the phycocyanin pigment composition containing phycocyanin and a metal or a metal compound was insoluble in water, and thus the present invention was accomplished.