A radiation-curable ink jet composition contains a polymerizable compound, a white pigment, and inorganic particles different from the white pigment. The polymerizable compound includes a monofunctional polymerizable compound. The content of the monofunctional polymerizable compound is 80 mass % or more with respect to the total mass of the polymerizable compound contained in the radiation-curable ink jet composition.

An inkjet recording apparatus and an inkjet recording method are provided that facilitate designing of units for subsequent treatment in terms of their shapes and/or positions, while suppressing variability in image quality resulting from subsequent treatment. Two or more recording heads are disposed in a staggered arrangement in X and Y directions. The paired units for subsequent treatment are disposed in parallel to each other along the X direction, and the recording heads are interposed between these units. The length of each of the units for subsequent treatment in the X direction is greater than or equal to the ink-dischargeable extent in the X direction of the recording heads in one scan. The recording heads are arranged, so that nozzle groups, from which the droplets of the same color are discharged, are disposed symmetrically with respect to an intermediary line between the paired units for subsequent treatment.

White-balance is improved when printing on colored media, while minimizing the time and use of costly materials required by present approaches. In an embodiment, the typical solid white fill or background layer is altered by including in the white layer one or more of the other colors already available in the printer to shade this layer. Thus, a small amount of cyan, for example, helps balance a pink-ish (red) media; yellow is used for blue media; and magenta is used for green media; as well as combinations thereof. A combination of transparent process inks and opaque white helps to maintain brightness (luminosity).

A system (20) and method for printing on clear polymeric film web (24) are disclosed. A first stationary inkjet print unit (44, 60, 70, 82) has first ejection nozzles that span a width of the clear polymeric film web and a second stationary inkjet print unit (44, 60, 70, 82) has second ejection nozzles that span the width of the clear polymeric film web. A web transport conveys the clear polymeric film web past the stationary inkjet print units. First and second print controllers operate the first and second and stationary inkjet print units to deposit drops of a first and a second material on the clear polymeric film web at a first and a second resolution, respectively. In addition, dimensions and position of a page element to be printed on the clear polymeric film web are adjusted to compensate for distortion that may occur to the printed page element due to shrinking of the clear polymeric film web.

An active energy ray-curable ink including a radical polymerizable monomer, a radical polymerization initiator, a pigment, a pigment dispersing resin, an organic onium salt, and a radical polymerization inhibitor, wherein the content of the radical polymerization inhibitor is 0.05% to 5.0% by mass of the total amount of the active energy ray-curable ink and an image recording method.

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 recording apparatus includes a white ink jet head, a non-white ink jet head, and a control section that controls performing recording by performing a main scan a plurality of times in which, while a position of an ink jet head relative to the recording medium is moved, an ink composition is ejected from the ink jet head and is applied to the recording medium. The control section performs recording in a first recording mode in which the white ink composition and the non-white ink composition are applied to the same scan region of the recording medium by the same main scan and recording in a second recording mode in which the white ink composition and the non-white ink composition are applied to the same scan region of the recording medium by different main scans.

The width by which the first, second heads overlap each other cross-sectionally along the first direction is greater than the width by which the fifth, sixth heads overlap each other cross-sectionally along the first direction.

An ink set has two or more aqueous pigment-based inks, each of which has 75-95 weight %, a) one or more pigment colorants, and b) one or more water-miscible humectants that are present in a total amount of at least 1 weight % and up to and including 20 weight %, and consist essentially of compounds, each of which has a carbon atom to oxygen atom ratio of at least 1.0:1.0 and only two hydroxy groups. The weight % amounts of water and the b) water-miscible humectants are based on the total weight of each aqueous pigment-based ink. The aqueous pigment-based inks in the ink set can be used individual or in combination to provide monochrome or polychrome inkjet-printed images on various ink-receptive media and using various inkjet printing equipment and methods.

The present invention relates to an ink-jet printing method of overprinting a first ink and a second ink on a low-liquid absorbing printing medium, in which the first ink and the second ink are respectively in the form of a water-based ink containing a colorant (A), a polymer (B), an organic solvent (C) and water, and satisfy the following formulae (1) and (2), said ink-jet printing method including the steps of forming characters or images using at least one ink as the first ink, and then forming a background image using the second ink such that the background image is superimposed on at least a part of the characters or images formed by the first ink: [T.sub.2−T.sub.1]<0 mN/m (1); and [V.sub.2−V.sub.1]≥1.0 mPa.Math.s (2) wherein T.sub.2 is the static surface tension of the second ink; T.sub.1 is the static surface tension of the first ink; V.sub.2 is the viscosity of the second ink as measured at 32° C.; and V.sub.1 is the viscosity of the first ink as measured at 32° C. According to the method of the present invention, it is possible to obtain good printed characters or images that are excellent in uniformity of solid image printing and suffer from less intercolor bleeding.