Ink delivery system

A writing instrument, comprising:

• a barrel having a barrel first end and an oppositely disposed barrel second end;
• an ink reservoir disposed within the barrel;
• a writing nib in fluid communication with the ink reservoir;
• a valve comprising a valve first end and an oppositely disposed valve second end;
• a valve stem having a stem first end and an oppositely disposed stem second end, wherein the stem first end is coupled to the valve;
• and
• an agitator disposed on the valve stem,
• wherein:
• the nib is coupled to the valve at the valve first end and the valve stem is coupled to the valve at the valve second end,
• the nib is adapted to actuate to shift the valve between first and second positions,
• when in a first position the valve is disposed in the barrel such that at least a surface of the valve seals against an internal surface of the barrel to prevent flow between the ink reservoir and the nib, and when in a second position, the valve is shifted to open one or more passages through which a fluid can flow from the ink reservoir to the nib, and
• a spring disposed around a stem clip attached to the valve stem biases the valve stem in the first position and actuation of the valve stem to the second position compresses the spring.