Disclosed is an ink jet recording ink set having light color inks of a plurality of colors and dark color inks of a plurality of colors. Each of the light color inks has at least a pigment, a solvent and a fine polymer particle and each of the dark color inks having at least a pigment and a solvent. Furthermore, each of the dark color inks either do not contain a fine polymer particle or contain a fine polymer particle in smaller quantity than the light color inks.

The invention relates to a process for producing a high-quality ink-jet recorded image. The process comprises the steps of (i) applying a first ink containing at least one colorant to an opaque printing medium by an ink-jet method to form a visible image; and (ii) applying a second ink, which does not change or substantially not change the hue of the printing medium, to a portion of the printing medium that is complementary to the visible image, thereby alleviating a difference in gloss between the visible image and the portion complementary to the visible image.

The present invention is drawn to a print medium and a method of preparing the same. The print medium can include a media substrate, a porous ink-absorbing layer coated on the media substrate, and a porous ink-receiving layer coated on the porous ink-absorbing layer. The porous ink-absorbing layer can include semi-metal oxide or metal oxide particulates and a first binder, and the porous ink-receiving layer can include organosilane-functionalized semi-metal oxide or metal oxide particulates and a second binder.

The present invention provides a method for manufacturing an ink jet recording head utilizing ink bubbling by heating of an exothermic resistor to thereby eject ink and a method manufacturing the same, including the steps of: preparing a substrate provided with the exothermic resistor; applying such first resin on the substrate as to provide a first mold shape for forming the nozzle channel and the movable member; forming the first mold shape using the first resin; applying, on the substrate, second resin over the first mold shape for forming the nozzle channel and the movable member; and removing the first mold shape. By this method, the movable member is formed in the nozzle channel between the ink inlet and the exothermic resistor to thereby provide a high-density, high-accuracy ink jet recording head which can improve a frequency response while maintaining proper discharge performance.

Techniques for fabricating an inkjet printhead include providing a printhead substrate (100), fabricating a thinfilm structure (101) on the substrate, forming a break trench (124) in a surface region of the substrate in which a feed slot is to be formed, and subsequently abrasively machining the substrate through the break trench to form the feed slot (126). The break trench can be formed by an etch process, prior to applying a barrier layer (112) to the thinfilm structure in a preferred embodiment.

An ink composition comprising a dispersion medium and a charged particle, wherein the charged particle comprises a colorant, a compound having pKb of 16 or less in water and containing a proton-acceptive neutral functional group, and a charge controlling agent having pKa of 16 or less in water and containing a proton-donative group.

The invention provides a liquid container (11) capable of supplying ink to the exterior until the ink is almost depleted, and allowing simple detection of the remaining ink amount and deviated distribution of the ink component after a prolonged standing. The liquid container is provided with a first connection port (27) and a second connection port (28) on the bottom, communicating with a liquid chamber. The connection port is positioned closer to the end of the container bottom, while the connection port is positioned closer to the center thereof. In the connection ports, elastic members (16) are provided so as to prevent leakage of the ink in the liquid chamber.

The present invention relates to an ink composition and a respective varnish, suitable for use in heatset printing, in particular heatset web offset printing, which is suited to avoid fluting during the printing process. The ink composition comprises at least one solvent having a boiling point of from 200°C to 240°C which is present in an amount suited to allow the ink composition to dry at a printed web temperature of from 40°C to 60°C during the printing process to avoid fluting.

The present invention relates to an ink composition and a respective varnish, suitable for use in heatset printing, in particular heatset web offset printing, which is suited to avoid fluting during the printing process. The ink composition comprises at least one solvent having a boiling point of from 200°C to 240°C which is present in an amount suited to allow the ink composition to dry at a printed web temperature of from 40°C to 60°C during the printing process to avoid fluting.

The ink cartridge (10) has an ink chamber and an elastic insert in a channel opening into the chamber and clamped against a stop in the axial direction so that the end of the insert not in contact with the stop is held in contact with a porous ink reservoir , whereby the porous insert is deformed by the clamping force so that its mean pore size is less than/equal to that of the ink reservoir.