A gel pen is a type of pen that uses a water-based gel ink. This type of ink is thicker and more viscous than the ink used in ballpoint pens or rollerball pens. Gel pens are known for their smooth writing, vibrant colors, and the ability to produce fine lines. Here are some key features and characteristics of gel pens:

1. Ink Type: Gel pens use a gel-based ink that is water-based and pigmented. The ink is suspended in a gel-like substance, providing a smooth and consistent flow.

2. Smooth Writing: Gel pens are known for their smooth writing experience. The gel ink glides easily onto paper, making them a popular choice for various writing tasks.

3. Vibrant Colors: Gel pens are available in a wide range of colors, including bold and vibrant shades. This makes them popular for artistic and creative applications, as well as for color-coding notes.

4. Fine Lines: Gel pens can produce fine lines, making them suitable for detailed writing and drawing. They are often available in different tip sizes, such as 0.5mm, 0.7mm, or 1.0mm, allowing users to choose the thickness of the lines they prefer.

5. Quick Drying: Gel ink tends to dry quickly, reducing the likelihood of smudging or bleeding through the paper.

6. Variety of Designs: Gel pens come in various designs, including retractable, capped, and refillable options. Some gel pens also have special features such as grip cushions for added comfort during extended use.

7. Uses: Gel pens are versatile and can be used for a variety of writing tasks, including note-taking, journaling, drawing, and more.