Brush pens are versatile writing tools that combine the features of a traditional brush and a pen. They have flexible tips that allow for varying line thickness, making them ideal for calligraphy, lettering, and illustrations. The ink is usually water-based, which enables smooth application and easy blending with other colors. These pens come in various styles, including felt-tip and watercolor options, catering to different artistic needs. Many artists and hobbyists prefer brush pens for their convenience and portability, as they do not require additional tools like brushes or ink pots. They are popular for both professional and casual use.