Pen set features a dual-sided design to provide both a flexible brush tip and fine tip in one. Brush tip works like a paintbrush to create fine, medium or bold strokes. Plus, the resilient nylon brush retains its point stroke after stroke for long-lasting use. Fine tip lets you create precise, consistent lines. Water-based, acid-free ink is blendable to let you create your own unique colors. Pens are perfect for use by artists, crafters and more.