Ink refills are cartridges or containers filled with ink that can be used to replenish the ink supply in writing instruments like fountain pens, rollerball pens, and ink pens. They come in various types, including disposable and reusable options, allowing users to choose based on their preferences and environmental considerations. Using ink refills is a cost-effective and sustainable way to extend the life of your writing tools. Instead of buying a new pen, you can simply replace the ink, which reduces waste and saves money. Many brands offer a variety of colors and ink types to suit different writing styles.