Creative, versatile, vibrant, & durable best describe these PRO Dual Tip Brush Pens. Create broad strokes, fine lines, & everything in between, simply by changing ends or brush pressure. These pens are acid-free, non-toxic, & odorless. The caps are color coded, air tight, & anti-roll. The ink is water-based and blends easily. Use two or more markers to create unique shades & the colorless blender pen for watercolor effects. use these pens for any art project or inspired moment & no messy cleanup!