The present disclosure provides an inkjet ink and primer fluid set containing an aqueous primer composition and aqueous inkjet inks. The aqueous primer composition forms a coating on a print substrate. The inkjet inks contain a polymeric binder that interacts with the primer composition. This fluid set is particularly suitable for printing on non-porous plastic substrate.

An ink set according to the present disclosure includes: a treatment liquid containing an aggregating agent; a deep ink composition; and a light ink composition, the ink compositions containing colorants, belonging to the same color system, and each being a water-based ink jet ink, the light ink composition contains an organic solvent which is a condensate of an alkanediol having 2 or 3 carbon atoms and which has two hydroxy groups, and the deep ink composition contains an organic solvent which is an alkanediol having 2 to 4 carbon atoms.

An ink set according to the present disclosure includes: a treatment liquid containing an aggregating agent; a deep ink composition; and a light ink composition, the ink compositions containing colorants, belonging to the same color system, and each being a water-based ink jet ink, the light ink composition contains an organic solvent which is a condensate of an alkanediol having 2 or 3 carbon atoms and which has two hydroxy groups, and the deep ink composition contains an organic solvent which is an alkanediol having 2 to 4 carbon atoms.

A recording method includes: a white ink attachment step of ejecting a white ink composition containing a white coloring material from a white ink jet head and attaching the white ink composition to a recording medium; a non-white ink attachment step of ejecting a non-white ink composition containing a non-white coloring material from a non-white ink jet head and attaching the non-white ink composition to the recording medium; and a primary drying step of heating the white ink composition and the non-white ink composition attached to the recording medium by a drying mechanism. In the white ink attachment step and the non-white ink attachment step, a layer containing the white ink composition and the non-white ink composition is formed by performing main scanning multiple times, in which the ink compositions are ejected and attached to the recording medium, and by attaching the white ink composition and the non-white ink composition to the same scanning region in the recording medium by the same main scanning, while moving a position of an ink jet head relative to the recording medium.

A liquid composition includes an inorganic particle and a multivalent metal salt, wherein the liquid composition has a tacking force of 50 mN or less in an area of cast-coated paper where the liquid composition is applied in an amount of 0.12 mg/cm.sup.2 for the cast-coated paper followed by heating at 80 degrees C. for 15 seconds.

An image-recording apparatus includes: a first tank defining a first storage chamber; a second tank defining a second storage chamber; a conveying mechanism for conveying sheets along a conveying path extending in a depthwise direction and a widthwise direction perpendicular to a vertical direction and the depthwise direction; and a recording head including a nozzle. Liquid in the first storage chamber is supplied through a communication port to the second storage chamber and then to the recording head through a liquid outlet port. The second storage chamber is positioned further in a first depthwise direction relative to the nozzle and further in a first widthwise direction relative to the conveying path. A volume of a prescribed space above a liquid level equal to a height of the communication port in the second storage chamber is greater than that of a liquid channel between the liquid outlet port and the nozzle.

An image-recording apparatus includes: a first tank defining a first storage chamber; a second tank defining a second storage chamber; a conveying mechanism for conveying sheets along a conveying path extending in a depthwise direction and a widthwise direction perpendicular to a vertical direction and the depthwise direction; and a recording head including a nozzle. Liquid in the first storage chamber is supplied through a communication port to the second storage chamber and then to the recording head through a liquid outlet port. The second storage chamber is positioned further in a first depthwise direction relative to the nozzle and further in a first widthwise direction relative to the conveying path. A volume of a prescribed space above a liquid level equal to a height of the communication port in the second storage chamber is greater than that of a liquid channel between the liquid outlet port and the nozzle.

A method of printing a stealth white image includes applying a stealth ink containing a red coloring material that emits visible light at exposure to ultraviolet radiation and a green coloring material that emits visible light at exposure to ultraviolet radiation to a substrate which contains a fluorescent brightener to form the stealth white image thereon, wherein the stealth white image demonstrates an a* value of from −2.0 to 2.0 and a b* value of from −10.0 to 0 at exposure to ultraviolet radiation having a wavelength of 370 nm according to CIE 1976 L*a*b* colorimetric system.

A method of printing a stealth white image includes applying a stealth ink containing a red coloring material that emits visible light at exposure to ultraviolet radiation and a green coloring material that emits visible light at exposure to ultraviolet radiation to a substrate which contains a fluorescent brightener to form the stealth white image thereon, wherein the stealth white image demonstrates an a* value of from −2.0 to 2.0 and a b* value of from −10.0 to 0 at exposure to ultraviolet radiation having a wavelength of 370 nm according to CIE 1976 L*a*b* colorimetric system.

An aqueous polyurethane resin dispersion, the polyurethane resin is obtainable by reacting an allophanate based isocyanate according to general formula I or II, optionally a polyether diol, a polyol containing a quaternary N-atom or tertiary amino group and a polyol selected from the group consisting of polyester polyol, polyether polyol, polycarbonate polyol, a polyacrylate polyol, a polyolefin and a polyamide polyol. The polyurethane resin is suitable as a resin in treatment liquids of substrates and images made by inkjet printing.

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