Abstract: A writing instrument includes a hollow elongated body with a tip disposed proximate a bottom end portion of the body, a removable cartridge for containing elongated writing material, and an advancing mechanism for incrementally advancing the writing material into and outwardly beyond an opening in the tip. The cartridge can be inserted into and removed from an opening in the writing instrument body. The cartridge does not move with respect to the body when the writing material is advanced by the advancing mechanism. The cartridge includes a cartridge body with a writing material outlet hole, and can include a lid with a lid hole and a bumper portion. The lid can be configured to slide between a closed position, covering the outlet hole, and an open position, not covering the outlet hole. In the open position, writing material may exit through the outlet hole and advanced toward the tip by the advancing mechanism.

Abstract: A writing instrument ink cartridge. Preferred is a coil or wave shaped cartridge in various colors and configurations.

Abstract: A writing instrument ink cartridge is described. Preferred is a coil or wave shaped cartridge in various colors and configurations.