The alcohol based inks of Copic Ciao markers are permanent, non-toxic, low odor, and acid-free. They boast 2 nib ends-a Super Brush and a Medium Broad. Layering and blending colors can be done on many surfaces-paper, leather, wood, plastics, and more. Ciao markers have a 3-year shelf life and are guaranteed for consistency of color. Ciao’s are NOT compatible with the Copic Airbrush system.