Copic Sketch Marker B39 Prussian Blue The choice of professionals worldwide, the Copic Sketch marker offers outstanding performance in all areas of design and illustration. Two versatile tips produce a range of strokes from fine lines to wide color fills. The roll-proof flat barrel is filled with alcohol based ink for a long life. The Copic Sketch marker has a brush nib and a broad nib. Fast-drying, permanent, non-toxic, and toner compatible.