Abstract: A water-fast ink composition and method for making the same. A selected chemical dye having at least one functional group with an extractable hydrogen atom thereon (e.g. --COOH, --NH.sub.2, or --OH) is combined with an ammonium zirconium polymer salt (e.g. ammonium zirconium carbonate, ammonium zirconium acetate, ammonium zirconium sulfate, ammonium zirconium phosphate, and ammonium zirconium oxalate). The resulting mixture preferably contains about 0.01-5.0% by weight ammonium zirconium polymer salt and about 0.5-5.0% by weight chemical dye. Upon dehydration of the mixture, the ammonium zirconium polymer salt and chemical dye form a cross-linked dye complex which is stable and water-fast. The mixture may be dispensed onto a variety of substrates (e.g. paper) using thermal inkjet or other printing systems.

Abstract: A method and apparatus for rapidly determining the print quality of a porous material which includes contacting a porous surface with a source of ink, providing a known relative acceleration between said ink source and said porous surface, and thereby transferring a predetermined volume of ink from said ink source to a known area of said porous suface. Then, the amount of ink transferred into the porous surface area per unit of time is measured to thereby determine the time between initial ink contact and the initial ink penetration, referred to as wetting delay, and the penetration rate of ink into the porous surface.

Abstract: A piezoelectric pump or equivalent transducer is mounted on or within an ink jet printhead and is used to modulate the frequency or amplitude, or both, of oscillations of a liquid meniscus at a liquid ejection orifice of a nozzle plate. The liquid meniscus at the orifice has a natural resonant frequency and amplitude with respect to its equilibrium position, and the above modulation is performed in a controlled timed relation with respect to the phase of the natural oscillations of the meniscus at the liquid ejection orifice.

Abstract: A recording fluid for the ink jet process contains a water-miscible organic solvent and a dye of the formula ##STR1## where R.sup.1, R.sup.2, R.sup.3 and R.sup.4 each have specified meanings, An.crclbar. is an anion and X is a bridge member of the formula ##STR2## where Y and the rings A and B each have specified meanings.

Abstract: A recording fluid for the ink jet process contains a water-miscible organic solvent and a dye of the formula ##STR1## where m is 0 or 1,D.sup.1 and D.sup.2 are each independently of the other the radical of a diazocomponent of the aniline series,R.sup.1 is hydrogen or C.sub.1 -C.sub.4 -alkyl andR.sup.2 and R.sup.3 are each independently of the other a radical having an external basic group.

Abstract: A method and apparatus for rapidly determining the print quality of a porous material which includes contacting a porous surface with a source of ink, and then providing a known relative acceleration between the ink source and the porous surface. In this manner, a predetermined volume of ink is transferred from the ink source to a known area of the porous surface. Then, the amount of ink transferred into the porous surface area per unit of time is measured to thereby determine the time between initial ink contact and the initial ink penetration, referred to as the wetting delay, the penetration rate of ink into the porous surface, and the volumetric roughness of the porous material. All of these latter parameters are closely correlated to print quality.

Abstract: A dye used in ink compositions for ink-jet printing comprises an aromatic dye molecule having attached to the backbone thereof from one to four polyhydroxyl-substituted groups having the formula selected from the group consisting of:(a) CH.sub.2 OH-(CHOH).sub.n CH.sub.2 O-, where n=2 to 10;(b) O.sub.n-1 C.sub.n H.sub.2n-1 -O-, where n=5 to 7; and(c) C.sub.6n H.sub.5n+1 O.sub.5n -O-, where n=1 to about 100. These dyes have improved water solubility and improved interaction with paper.