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 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.

A writing instrument excellent in handwriting density and temporal stability. The writing instrument includes a ball-point pen tip attached to the front end portion of the ink storage cylinder; and a ball-point pen refill having an ink composition for a writing instrument loaded therein. The ink composition for the writing instrument is a thermochromic ink containing at least a thermochromic microcapsule pigment. The writing instrument includes a pressurization mechanism for applying a pressure to the back end of the ink composition for the writing instrument.

A writing instrument excellent in handwriting density and temporal stability. The writing instrument includes a ball-point pen tip attached to the front end portion of the ink storage cylinder; and a ball-point pen refill having an ink composition for a writing instrument loaded therein. The ink composition for the writing instrument is a thermochromic ink containing at least a thermochromic microcapsule pigment. The writing instrument includes a pressurization mechanism for applying a pressure to the back end of the ink composition for the writing instrument.

A writing instrument assembly has a writing instrument with a body and a working tip extended or extendable from the body. A holder has a landing spot for the writing instrument. The writing instrument is magnetically and detachably retained at the landing spot when attached to the holder. The working tip is sheathed or covered automatically when the writing instrument is attached to the holder and is unsheathed or uncovered when detached from the holder.

A writing instrument assembly has a writing instrument with a body and a working tip extended or extendable from the body. A holder has a landing spot for the writing instrument. The writing instrument is magnetically and detachably retained at the landing spot when attached to the holder. The working tip is sheathed or covered automatically when the writing instrument is attached to the holder and is unsheathed or uncovered when detached from the holder.

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]

The ink composition contains titanium oxide particles having an average particle size of 0.1 m or more and 0.4 m or less, hollow resin particles having an average particle size of 1.0 m or more and 2.0 m or less, a polysaccharide and water, wherein the titanium oxide particles and the hollow resin particles are negatively charged.

The ink composition contains titanium oxide particles having an average particle size of 0.1 m or more and 0.4 m or less, hollow resin particles having an average particle size of 1.0 m or more and 2.0 m or less, a polysaccharide and water, wherein the titanium oxide particles and the hollow resin particles are negatively charged.

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.