Abstract: An ink jet recording sheet comprising a paper support applied on at least one surface thereof or internally with a composition which comprises an aqueous dispersion of polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer or a mixture thereof serving as a binder or sizing agent and a white filler. The white filler is contained in a weight ratio, to the binder, of 10:1 to 0.2:1 when the composition is applied on the surface of the paper support. When the composition is internally incorporated in the recording sheet, it comprises 10 to 60 parts by weight of the filler and 2 to 20 parts by weight of the binder per 100 parts by weight of pulp.

Abstract: An ink jet recording sheet comprising a paper support applied on at least one surface thereof or internally with a composition which comprises an aqueous dispersion of polyvinylpyrrolidone, vinylpyrrolidone-vinyl acetate copolymer or a mixture thereof serving as a binder or sizing agent and a white filler. The white filler is contained in a weight ratio, to the binder, of 10:1 to 0.2:1 when the composition is applied on the surface of the paper support. When the composition is internally incorporated in the recording sheet, it comprises 10 to 60 parts by weight of the filler and 2 to 20 parts by weight of the binder per 100 parts by weight of pulp.

Abstract: In order to prevent clogging of the nozzle of an ink jet writing head, a nozzle moistening device is provided which includes an elastic enclosure fluid-tightly engageable with the front face of the writing head when not in use, a source of water, and a capillary tube for transmitting water from the source to the enclosure by capillary action to permit evaporation of water in the enclosure to moisten the nozzle.

Abstract: An ink composition for ink jet recording consisting essentially of a water-soluble wetting agent, water, a water-soluble dye and an oxygen absorber.

Abstract: A writing mechanism for applying fluid droplets to a surface includes a chamber which is divided into an outer chamber portion and an inner chamber portion with a channel connecting the outer and inner chamber portions. The inner chamber portion is provided with a device which produces short duration pressure increases in the fluid in the chamber. The outer chamber portion is provided with an intermediate reservoir chamber which is in communication with an intake channel for the supply of liquid from a supply container and a discharge channel through which the liquid is discharged for deposition on the surface.