Abstract: A specific dye set, comprising Acid Yellow 23, Acid Red 52, and Acid Blue 9, yields true, vivid colors on special coated paper. This dye set, which is intended for 180 dpi thermal ink-jet printers, such as Hewlett-Packard's PaintJet.RTM. printer, is a distinct improvement over a prior art dye set.

Abstract: A thermal ink jet print device having a phase change material, a solid or fluid, disposed in heat exchange proximity to the thermal ink jet printhead to absorb printhead heat energy by changing physical state at a printhead temperature below that at which unacceptable printing takes place and at a rate commensurate with the rate of heat energy input.

Abstract: A specific dye set, comprising Acid Yellow 23, Direct Red 227, and Acid Blue 9, yields true, vivid colors on specially coated paper and transparency, and yields true colors on uncoated or "plain" papers. This dye set, which is intended for 300 dpi thermal ink-jet printers, is a distinct improvement over a prior art dye set.

Abstract: A specific dye set, comprising Direct Yellow 86, Acid Red 52, and Acid Blue 9, yields true, vivid colors on transparency film and special coated paper. This dye set, which is intended for 180 dpi thermal ink-jet printers, is a distinct improvement over prior art dye sets.

Abstract: A specific dye set, comprising Acid Yellow 23, Direct Red 227, and Acid Blue 9, yields true, vivid colors on specially coated paper and transparency, and yields true colors on uncoated or "plain" papers. This dye set, which is intended for 300 dpi thermal ink-jet printers, is a distinct improvement over a prior art dye set.

Abstract: The properties of inks employing copper phthalocyanine dyes having associated therewith sodium cations are improved by replacing the sodium cations with potassium cations. This ion exchange is preferably performed by passing a potassium-containing base through a strong acid resin to replace the H.sup.+ ions with K.sup.+ ions. The dye is then passed through the potassium-loaded resin to effect the ion exchange. Inks made from the potassium-substituted dyes evidence reduced crusting, increased idle time without causing drop ejection failures (soft plugs) and improved kogation without suffering any loss in print quality.

Abstract: Inks used in ink-jet printing comprise a vehicle and a dye. The vehicle consists essentially of about 5 to 10 wt % of a glycol and/or glycol ether and the balance water. The dye is typically an anionic dye, associated with undesirable cations such as sodium or potassium cations. Several properties of such inks are improved by replacing substantially all of said cations on the anionic dye with lithium cations and removing such cations, preferably to leave a maximum concentration of such cations of less than about 500 ppm, and most preferably less than about 350 ppm.

Abstract: Inks used in ink-jet printing comprise a vehicle and a dye. The dye is typically an anionic dye, associated with undesirable cations such as sodium or potassium cations. Several properties of such inks are improved by replacing at least about one-fourth of such cations on the anionic dye with tetramethylammonium cations.