The present invention provides an aqueous writing ink composition capable of forming handwriting having both opacity and transparency, also a writing implement using the composition, and further a process for producing the composition. The aqueous writing ink composition according to the present invention comprises a white pigment, resin particles containing styrene-acrylonitrile, a colorant, and a polysaccharide. The content of the white pigment X %, that of the resin particles Y.sub.1% and that of the polysaccharide Y.sub.2% satisfy the conditions of

0.1X7,[1]

0.5<(Y.sub.1+Y.sub.2)/X, and[2]

102.5X+(Y.sub.1+Y.sub.2)40.[3]

A paint pen having a squeezable paint reservoir, a flexible and resilient tube connected at one end to the reservoir and at the other end to a tip comprising an absorbent and permeable material (relative to the paint in the reservoir) is disclosed. The pen operates by squeezing the tube to provide paint through the tube to the tip at which point it can be applied to a surface. The flexibility and resilience of the tube enables uniform application of the paint to rough surfaces.

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.

A writing instrument configured to apply a writing material or liquid to a surface, comprising a socket, and a ball arranged in the socket, characterized by at least one first component which is arranged to come into contact with the ball, wherein the at least one first component comprises a first material having surface properties such that the friction coefficient between the ball and the at least one first component decreases when the force acting from the ball on the at least one first component increases at least within a certain range of forces.

A ballpoint pen is provided in which the width of the drawing line can be changed, wherein responsiveness can be improved when distinguishing between drawing thin lines and thick lines. A ballpoint pen 1 provided at the pen tip side with a first writing part having a writing ball 25, wherein the ballpoint pen 1 is characterized by being provided with a writing part at the pen tip side with which it is possible to write a thicker line than the line written with the first writing part, only the first writing part being used when the writing weight is 1 g and the writing angle is 90, and the second writing part being used when the writing weight is 200 g, and the writing angle is 40-90.

The present disclosure relates to a system comprising a writing instrument. The writing instrument comprises a ceramic writing ball. The ceramic writing ball comprises relative to the total weight of the ceramic writing ball about 1.0 wt.-% to about 14.6 wt.-% of one or more metal oxides selected from Y.sub.2O.sub.3, HfO, MgO, CaO and/or Ce.sub.2O.sub.3, about 0.15 wt.-% to about 3.0 wt.-% Al.sub.2O.sub.3, and ZrO.sub.2 as balance.

Embodiments of the invention are directed to a roller ball marking instrument for use with paint, a method for assembling the roller ball marking instrument, and a system for delivering paint. The body of the marking instrument includes a reservoir for storing paint. The body is coupled to a fibrous roller ball via a retaining ring. The roller balls sits within a partially-enclosed cavity in the center of the retaining ring. A least part of the roller ball protrudes through an opening in the retaining ring. Paint in the reservoir moves first through an opening at one end of the body and then through an open center of the retaining ring. The paint is transferred to the roller ball. The roller ball rotates freely within the cavity of the retaining ring and transfers the paint to a writing surface.

In order to provide a writing ball capable of suppressing wear of a ball seat of a ballpoint pen tip and obtaining stable ink outflow, a writing ball that is a sphere, the sphere comprising, at least: a first hard component containing a first metal; a second hard component containing a second metal; and a binding component, the writing ball comprising: a first outer surface from which the first hard component is exposed, the first outer surface being an outermost surface of the sphere; and a recess including, as a bottom surface, a second outer surface from which the second hard component is exposed, the second outer surface being recessed inward from the first outer surface, wherein the first outer surface includes a smooth surface is provided.

Disclosed are a knock type direct liquid pen refill assembly and a writing pen. The pen refill assembly comprises an ink cylinder assembly (100), a pen tip (200) and an elastic member (300). An ink guide core (150) is provided in the ink cylinder assembly. The pen tip (200) is arranged at one end of the ink cylinder assembly (100). An ink duct (210) is formed inside and passes through the pen tip (200). A ball member (230) is provided at an ink outlet end of the ink duct (210). The ink guide core (150) partially passes through the ink duct (210), and one end of the ink guide core (150) is abutted against the ball member (230). The elastic member (300) is sleeved at the periphery of the ink guide core (150) and positioned inside the ink duct (210). The elastic member is abutted against the ball member to exert a force, such that the ball member is closely attached to an inner wall of the ink outlet end, the ball member forms sealed contact with the inner wall of the ink outlet, and ink volatilization and leakage are avoided.

A writing ball capable of suppressing wear of a ball seat of a ballpoint pen tip and obtaining stable ink outflow, a writing ball that is a sphere, the sphere comprising, at least: a first hard component containing a first metal; a second hard component containing a second metal; and a binding component, the writing ball comprising: a first outer surface from which the first hard component is exposed, the first outer surface being an outermost surface of the sphere; and a recess including, as a bottom surface, a second outer surface from which the second hard component is exposed, the second outer surface being recessed inward from the first outer surface, wherein the first outer surface includes a smooth surface.