Gel inks are a type of ink used in pens that combine water-based dye with a thickening agent, creating a smooth and vibrant writing experience. They are known for their rich colors and ability to produce fine lines, making them popular for both everyday writing and artistic applications. Unlike traditional ballpoint inks, gel inks dry quickly and are less likely to smudge, which is beneficial for left-handed writers. They are available in various colors and tip sizes, allowing for versatility in writing styles and preferences.