Abstract: An ink refill device includes a body having a chamber with ink therein. The chamber has one wall formed of a frangible material. The body has a needle communicating the chamber with a reservoir, which has a foam of a controlled porosity therein, in a print cartridge when the needle is inserted in a vent of the reservoir to fill the reservoir. Breaking of the frangible wall of the chamber with the needle extending downwardly enables ink to flow from the chamber at a controlled flow rate to the reservoir in the cartridge. In the preferred embodiment, the needle has one or more notched openings adjacent its distal end to increase its surface area through which ink flows to increase flow of ink to the reservoir.

Abstract: A waterfast ink having 3.0% Food Black 2, 2.5% highly hydroxyethylated polyethyleneimine, 10.0% ammonium benzoate, and the balance water. The invention appears to function upon loss of water after printing by a polar neutralizing between the dye and the polyimine, which results in an affinity of the dye to paper. It is applicable to any dye having anionic solubilizing groups but not having quaternary ammonium and to any ammonium salt.

Abstract: A alkali-soluble dye for a waterfast ink having structural formula as follows: ##STR1## and an ink containing the dye dissolved in water. Printing from the ink is insoluble below pH 6.0; is an intense black at low concentration; and remains black on acid papers. The aqueous inks are stable and exhibit good printhead nozzle maintenance.