Copic Marker Sketch Stamping set is especially made for stamps. The markers have an alcohol based ink that is permanent, non-toxic, low odor and acid-free. Sketch Markers are the most popular of the Copic Markers. They are excellent for all forms of illustration, design, scrapbooks, fine art and more. Sketch markers have a 3-year shelf life and are guaranteed for color consistency. They can also be used with the Copic Airbrush system. Free Shipping.