Willow Sketching Charcoal. Willow charcoal is a traditional medium for drawing. It is often used alone or to layout sketches for painting. With it you can create velvety blacks; or blend and erase for dramatic shading. This package contains five assorted pure willow sketching charcoal sticks in a convenient plastic storage case; and one latex free; PVC free kneaded rubber eraser. Conforms to ASTM D 4236. Made in USA.