Anatomy of a fountain pen

I have been talking about fountain pens for long. However, I have never talked about the basic parts of a fountain pen. A fountain pen is made up of many parts and typically consists of :

Cap: The cap is the top part of the pen that covers the nib when it is not in use. It often screws onto the body of the pen to keep the ink from drying out. There are a number of cap closing mechanisms most common being pop on/off and screw on/off.

Barrel: The barrel is the main body of the pen that holds the ink reservoir. It can be made of various materials such as plastic, metal, or resin.

Section: A section or grip section is the part of fountain pen into which the nib fits in. Also section is the part from where the pen is held while writing.

Nib: The nib is the metal tip of the pen that comes into contact with the paper. It is typically made of stainless steel or gold and is designed to be flexible enough to provide varying line widths. Nibs come in different sizes and nib tip widths. e.g. Most common size for nibs is International No 6. The bin widths range from Extra fine(EF) to Trippel Broad(BBB). Most renowned pen making companies have proprietary nib sizes. 

Feed: The feed is a small plastic or ebonite piece that sits underneath the nib and regulates the flow of ink. It has a series of channels and fins that help distribute the ink to the nib.

Ink reservoir: The ink reservoir is the part of the pen that holds the ink. It can be a piston reservoir, a converter, cartridge, or built-in ink reservoir.

Filling mechanism: The filling mechanism is the way the pen is filled with ink. There ae many types of filling mechanisms. Most common are piston, removable converter, cartridge and eyedropper.  

Clip: The clip is a small metal or plastic piece that attaches to the cap and allows the pen to be clipped onto a pocket or notebook for easy carrying.

A fountain pen is a complex instrument that requires precise engineering to create a smooth and enjoyable writing experience.