An erasable ink set includes: an erasable ink; and an erasing time adjuster which is stored separately from the erasable ink and is capable of adjusting an erasing time of the erasable ink. The erasable ink includes a color developing agent including a pH indicator, water, and at least one selected from the group consisting of a first water-soluble organic solvent and a first surfactant. The erasing time adjuster includes water and at least one selected from the group consisting of a second water-soluble organic solvent and a second surfactant.

An aqueous composition can be used for pre-treating a substrate prior to inkjet printing to provide a white opaque background for inkjet-printed images. This aqueous composition includes: (a) one or more water-soluble salts of a multivalent metal cation at 5-30 weight %; (b) a nonionic or cationic water-soluble or water-dispersible polymeric binder material at 5-30 weight %; and (c) surface-treated visible light-scattering particles having a D.sub.50 (median) particle size of at least 0.04 μm and up to and including 2 μm in an amount of 5-60 weight % based on the total aqueous composition weight. The pre-treated substrate is useful as an inkjet receiving medium that can be readily inkjet-printed particularly with anionically-stabilized aqueous pigment-based inks.

A pretreatment liquid that is used together with an aqueous inkjet ink containing a pigment and water, wherein the pretreatment liquid contains resin microparticles (A), a surfactant (B), a coagulant (C) and water, the surfactant (B) contains a polyoxyalkylene alkyl ether (b-1), and the coagulant (C) contains a polyvalent metal salt and/or a cationic polymer compound and has a water absorptivity at a temperature of 40° C. and a relative humidity of 80% of 75% by mass or less.

A pretreatment liquid that is used together with an aqueous inkjet ink containing a pigment and water, wherein the pretreatment liquid contains resin microparticles (A), a surfactant (B), a coagulant (C) and water, the surfactant (B) contains a polyoxyalkylene alkyl ether (b-1), and the coagulant (C) contains a polyvalent metal salt and/or a cationic polymer compound and has a water absorptivity at a temperature of 40° C. and a relative humidity of 80% of 75% by mass or less.

An image forming apparatus contains an ink having a dynamic surface tension of from 30 to 50 mN/m at a life time of 15 msec at 25 degrees C., a container containing the ink and a head configured to discharge the ink to a fabric including a first fabric containing synthetic fiber in an amount of more than 50 percent by mass and a second fabric containing natural fiber in an amount of 50 percent by mass or greater, the head including a nozzle surface, wherein a first distance between positions of two consecutive droplets of the ink discharged from the head on the first fabric is shorter than a second distance between positions of two consecutive droplets of the ink discharged from the head on the second fabric.

Provided are ink-receptive coating compositions including: (a) an aqueous anionic polyurethane dispersion; and (b) an aqueous solution of a nonionic polyurethane. Methods of coating substrates, and of printing, including providing and/or coating the composition onto a substrate are also provided.

Provided are ink-receptive coating compositions including: (a) an aqueous anionic polyurethane dispersion; and (b) an aqueous solution of a nonionic polyurethane. Methods of coating substrates, and of printing, including providing and/or coating the composition onto a substrate are also provided.

An ink set including an ink containing water, a pigment, a pigment dispersion polymer A, and a water-soluble polymer B, and a treatment liquid containing water and at least one selected from the group consisting of a polyvalent metal salt, an acidic compound, and a cationic polymer, in which the pigment dispersion polymer A contains a specific acid group and an aromatic ring, and the water-soluble polymer B contains a specific acid group and a constitutional unit represented by General Formula (1), and in the ink, a mass ratio of a content concentration of the water-soluble polymer B to a content concentration of the pigment dispersion polymer A in a liberated polymer is 1.6 or more, and an image recording method. R.sup.1 represents a hydrogen atom or a monovalent substituent, Y.sup.1 represents a monovalent substituent, A.sup.1 represents —O—, and L.sup.1 is a divalent linking group.

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An ink set including an ink containing water, a pigment, a pigment dispersion polymer A, and a water-soluble polymer B, and a treatment liquid containing water and at least one selected from the group consisting of a polyvalent metal salt, an acidic compound, and a cationic polymer, in which the pigment dispersion polymer A contains a specific acid group and an aromatic ring, and the water-soluble polymer B contains a specific acid group and a constitutional unit represented by General Formula (1), and in the ink, a mass ratio of a content concentration of the water-soluble polymer B to a content concentration of the pigment dispersion polymer A in a liberated polymer is 1.6 or more, and an image recording method. R.sup.1 represents a hydrogen atom or a monovalent substituent, Y.sup.1 represents a monovalent substituent, A.sup.1 represents —O—, and L.sup.1 is a divalent linking group.

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By the use of an ultraviolet curable inkjet ink set for a line head printer comprising a lower layer ink containing a polymerizable monomer having a specific structure, and, a specific photopolymerization initiator, and an upper layer ink containing a polymerizable monomer having a specific structure and a specific photopolymerization initiator, wherein among the lower layer ink and the upper layer ink, one of the inks is a white ink and the other ink is a black ink, a good printed matter having excellent adhesion between a recording medium and the ink layer, and, between different ink layers can be obtained without generating curing wrinkles and curling over time even during high speed printing.