DUAL TIPS: Brushes tip for shading and coloring; 0.4 mm fine point tip for outlining and detail. So you get both colored brush markers and colorful fine liners pen, which are nice art pens for kids and adult. Flexible Brush Tip Durable and flexible nylon fiber brush tip, creates medium or bold strokes by changing brush pressure. It works like a paintbrush tocreate fine, medium or bold strokes ideal for lettering. Fine Tip At the other end of each Dual Brush Pen is the fine tip for consistent thin lines. Strong and un-mash-able, the fine tip is perfect for adding colorful details and journaling. Advantage: Deal for fine art, illustrations, doodling, journaling, hand lettering and more The ink is acid-free, non-toxic, blend able, odorless, and non-bleeding. Top quality water based ink allows you to work with other water-soluble material without bleeding, and frees you from any smear and smudge since it gets dried quickly