Patent ID: 7070352

Claim:
A writing implement in which liquid for ink and colorant are separately stored, comprising: a cylindrical shaft member; a pen tip member which is fixed to one end of the shaft member and from which colored ink seeps out; the liquid for ink which is stored in the shaft member and which comprises a major component of the colored ink seeping out from an end of the pen tip member; the colorant to be added to the liquid for ink to be the colored ink, located between the tip member and the liquid for ink; and a valve member for isolating the colorant from the liquid for ink; wherein at least a part of a cylindrical side surface of the shaft member corresponding to a part where the liquid for ink is stored is formed to be transparent; wherein the valve member is positioned between the storing part of the liquid for ink and the colorant; and wherein the storing part of the liquid for ink is provided with a pressure-regulating part for preventing an increase or decrease of a pressure in the storing part.