What are pen fins for and how do they contribute to the overall functionality of the pen?

Pen fins are small, ridged structures located near the tip of a pen. They help to regulate the flow of ink onto the paper by creating a consistent and smooth writing experience. The fins also help to prevent the pen from leaking or blotting, ensuring that the ink is distributed evenly and cleanly. Overall, pen fins contribute to the functionality of the pen by improving writing precision and reducing the likelihood of smudges or ink spills.