A liquid ink instrument, including: a pen body, a writing element mounted on the head of the pen body, an ink absorber mounted at the rear end of the writing element; a fiber ink feeder mounted in the body penetrates the ink absorbing body, the front end in contact with the writing element, the rear end communicated with the ink cartridge; at least one air-liquid balancer in the axial direction, the air-liquid balancer installed between the recited fiber ink feeder and the body; having one or more air-liquid exchange grooves penetrating through the outer circumferential surface; having an overflow groove on a radial surface of the air-liquid balancer, one end contacted to fiber ink feeder, and the other end communicating with air-liquid exchange groove; a gas-free fit or an interference fit adopted between the outer circumferential surface of the fiber ink feeder and the inner wall of the air-liquid balancer.

A dry-erase marker comprising a cylindrical housing configured to store an ink and a conic housing coupled to the cylindrical housing on a first end and having a socket on a second end. The dry-erase marker further comprising a marker head contained in the socket of the conic housing, where the marker head comprises a polymeric material and a surface topology. The conic housing is configured to transfer the ink from the cylindrical housing to the marker head, and the marker head is configured to transfer the ink to a dry-erase board by rotating in the socket.

A dry-erase marker comprising a cylindrical housing configured to store an ink and a conic housing coupled to the cylindrical housing on a first end and having a socket on a second end. The dry-erase marker further comprising a marker head contained in the socket of the conic housing, where the marker head comprises a polymeric material and a surface topology. The conic housing is configured to transfer the ink from the cylindrical housing to the marker head, and the marker head is configured to transfer the ink to a dry-erase board by rotating in the socket.

A liquid ink instrument, including: a pen body, a writing element mounted on the head of the pen body, an ink absorber mounted at the rear end of the writing element; a fiber ink feeder mounted in the body penetrates the ink absorbing body, the front end in contact with the writing element, the rear end communicated with the ink cartridge; at least one air-liquid balancer in the axial direction, the air-liquid balancer installed between the recited fiber ink feeder and the body; having one or more air-liquid exchange grooves penetrating through the outer circumferential surface; having an overflow groove on a radial surface of the air-liquid balancer, one end contacted to fiber ink feeder, and the other end communicating with air-liquid exchange groove; a gas-free fit or an interference fit adopted between the outer circumferential surface of the fiber ink feeder and the inner wall of the air-liquid balancer.

An aqueous ink composition suitable for a writing instrument may provide a handwriting formed by writing and capable of withstanding repeated scratching and scratching with a stronger force, and a writing instrument charged with the aqueous ink composition. An aqueous ink composition for a writing instrument may include at leas, a colorant (A) containing a pigment, olefin-based resin particles (B), and water. The olefin-based resin particles (B) may have a penetration method hardness of 1 or more and an average particle size of 15 ?m or less as measured by a Coulter counter method, and a solid content (A)/(B) mass ratio between the colorant (A) and the olefin-based resin particles (B) may be in a range of 1 to 100.

An aqueous ink composition suitable for a writing instrument may provide a handwriting formed by writing and capable of withstanding repeated scratching and scratching with a stronger force, and a writing instrument charged with the aqueous ink composition. An aqueous ink composition for a writing instrument may include at leas, a colorant (A) containing a pigment, olefin-based resin particles (B), and water. The olefin-based resin particles (B) may have a penetration method hardness of 1 or more and an average particle size of 15 ?m or less as measured by a Coulter counter method, and a solid content (A)/(B) mass ratio between the colorant (A) and the olefin-based resin particles (B) may be in a range of 1 to 100.

An oil-based ballpoint pen includes: a ballpoint pen tip at a tip part of an ink storage cylinder, and an oil-based ballpoint pen ink composition stored in the ink storage cylinder, the oil-based ballpoint pen ink composition containing a colorant, an organic solvent having a boiling point of 140? C. or lower, and a resin, wherein the oil-based ballpoint pen ink composition has an ink viscosity of 300 mPa.Math.s or less at 20? C. and a shear rate of 200 sec.sup.?1, an ink consumption of the oil-based ballpoint pen per a writing distance of 100 m is 80 mg or more, and a ratio of a ball diameter B (mm) to an ink consumption A (mg) per a writing distance of 100 m satisfies 100<A/B<600.

Provided are an ink composition for an aqueous ink ball point pen, which contains modified polyvinyl alcohol and at least one selected from boric acid and salts thereof, and an aqueous ink ball point pen charged with the ink composition, wherein the boric acid and the salts thereof are preferably at least one selected from boric acid, alkali metal salts of boric acid and ammonium salts of boric acid.

Provided are an ink composition for an aqueous ink ball point pen, which contains modified polyvinyl alcohol and at least one selected from boric acid and salts thereof, and an aqueous ink ball point pen charged with the ink composition, wherein the boric acid and the salts thereof are preferably at least one selected from boric acid, alkali metal salts of boric acid and ammonium salts of boric acid.

High opacity permanent ink formulations comprising a solvent, a polymer-based opacifier, a coloring agent, a resin, and a humectant, wherein the ink formulation displays a viscosity of less than about 50 cP, are provided herein.