A pen is a common writing instrument that has been used for centuries. It is composed of several parts, each made from different materials to ensure its functionality and durability.
Firstly, the barrel, which is the main body of the pen, is often made from plastic or metal. Plastic is lightweight and can be molded into various shapes and colors, making it a popular choice for everyday pens. Metal barrels, on the other hand, are more durable and often used in higher-end pens.
Secondly, the ink cartridge or refill is a crucial component. It is typically made from plastic and contains the ink that flows to the tip of the pen. The ink itself is usually a water-based or oil-based liquid with pigments or dyes that provide color.
The tip or nib of the pen, which dispenses the ink onto the paper, can be made from different materials depending on the type of pen. Ballpoint pens have a small rotating ball made of brass, steel, or tungsten carbide. Fountain pens have a nib made of stainless steel or gold, which provides a smooth writing experience.
Additionally, the cap or retractable mechanism, which protects the tip and prevents the ink from drying out, is also made from plastic or metal. The clip, which allows the pen to be attached to a pocket or notebook, is usually made of metal for strength and flexibility.
Overall, the design and materials used in a pen can vary significantly, but each component is carefully chosen to create a writing tool that is both functional and comfortable to use.