This artist-quality velvety, smooth pure vine charcoal is ideal for sketching smokey grays and blacks for soft charcoal drawings and layouts. Approximate diameter of the thin stick is 3 to 4mm, the medium stick is 5 to 6mm and the thick stick is 7 to 9mm. The willow charcoal sticks tube contains one thick, two medium and two thin 5-1/2" sticks.