The present invention provides: a highly practical and safe oil-based ink composition for a writing board, said composition being capable of imparting high mark-erasability and having excellent resistance to drying up; and a marking pen incorporating the same. Specifically, the present invention provides: an oil-based ink composition for a writing board, said composition containing a pigment, an organic solvent, a resin, and at least one compound selected from compounds represented by general formula (1) or (2); and a marking pen obtained by incorporating the oil-based ink composition for a writing board. (In the formulae, R.sup.1-R.sup.4 each represent a C6-18 alkyl group or a C2-18 and O2-10 alkoxypolyglycol group.)

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Provided is a writing implement having a pen tip that can achieve excellent ink outflow performance and an increase in the effective area of a viewer portion allowing recognition of the writing direction, relative to the whole pen tip. The writing implement is a writing implement A which includes a pen tip 20 feeding ink from a writing implement body 10 and having a viewer portion through which the writing direction can be recognized, and is characterized in that the pen tip 20 is configured of, a least, a writing part 30 and a holding body 40 having a viewer portion 43, and the holding portion 40 has a sheet-shaped ink feeder 25 formed with slits or bumps on the surface and inside thereof to produce a capillary action.

In a writing tool 1, a front shaft 5 is detachably provided on a rear shaft 6 containing an ink absorbent body 7. A filling part 51 is provided on an outside surface of a rear part of the front shaft 5. The filling part 51 detachably fits to a fitted part 61 formed on an inside surface of an opening part of the rear shaft 6. The filling part 51 has an outward-facing pressure contact part 53 and a radially penetrating slit 54. The fitted part 61 has an inward-facing pressure contact part 63. The front shaft 5 and the rear shaft 6 are brought into a pressure contact with each other when the front shaft 5 and the rear shaft 6 are fitted to each other.

Provided is aqueous ink composition for a writing instrument, which contains water and microspheres having a water-insoluble dye and a matrix constituted from a polymer wherein the water-insoluble dye is higher densely present in the inner part of the matrix than at the surface of the matrix, and at least one of the following (a) and (b) is satisfied: (a) the circularity coefficient of the microspheres, as measured by image analysis, is 0.6-1.0, and (b) the 10% strength of the microspheres, as determined in a micro-compression test, is 5-30 MPa.

Embodiments of the disclosure can include writing instruments, nibs for writing instruments, and methods of making the same. In one embodiment, the writing instrument includes a reservoir; an ink solution comprising a pigment, the ink solution being housed within the reservoir; a nib disposed at an end of the reservoir and plugging an opening of the reservoir such that the reservoir is closed, wherein a tip of the nib extends outside of the reservoir; and a filament extending within the reservoir, the filament being in fluid communication with a portion of the nib within the reservoir, such that the ink solution travels along the filament and through the nib, by capillary action, wherein the nib and filament are formed such that no more than 50 percent of the pigment present in the nib and filament flow into the reservoir outside of the nib and filament when the writing instrument is stored with the nib up for a period of one day.

A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib having an external surface configured to cooperate with an internal surface of the nib receiving part, the external surface being configured to allow intake of air from the outside of a free ink tank, the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank when cooperating with the internal surface of the nib receiving part. A valve-free free ink writing felt pen including a nib.

A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib having an external surface configured to cooperate with an internal surface of the nib receiving part, the external surface being configured to allow intake of air from the outside of a free ink tank, the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank when cooperating with the internal surface of the nib receiving part. A valve-free free ink writing felt pen including a nib.

A nib for a valve-free free ink writing felt pen including a first end configured to deliver ink to a writing support and second end, opposite the first end, configured to be inserted in a nib receiving part of the valve-free free ink writing felt pen, the first end and the second end defining an axial direction of the nib, the nib including a main body made of porous hydrophilic material and including one or more insert made of porous hydrophobic material, the one or more insert being configured to allow intake of air from the outside of a free ink tank of the valve-free free ink writing felt pen into the free ink tank and avoid ink leakage outside the free ink tank. A valve-free free ink writing felt pen including a nib.

A pen includes: an ink reservoir configured to store an ink; and a pen tip section including an ink application part configured to apply the ink to an ink application object. The ink application part of the pen tip section includes: a rigid tip made of a rigid material and having a hemispherical outer surface, an inner surface facing toward the ink reservoir, and a penetration part penetrating from the inner surface side to the outer surface side of the rigid tip; and at least one foam body filled in the penetration part at least on the side of the penetration part close to the outer surface side of the rigid tip, and provided with at least one air bubble formed to communicate from the outer surface side of the foam body to the inner surface side of the foam body.

An integrated highlighting marker includes a multi-component marker ink comprising a base colorant and a tinting colorant. The marking system also includes a highlighting component configured to transform the base colorant from a first colored state to a second colored state based on the tinting colorant. The highlighting component may be configured to transform the primary base colorant from a colored state to a transparent state to reveal the tinting colorant.