Willow charcoal is a long and thin charcoal stick that is the result of burning willow sticks in a kiln without air. It is made from the twigs of willow trees, burned to a degree of precise hardness for drawing. Willow charcoal usually comes in long sticks which vary in thickness – thin, medium, thick and chunky. It is much softer, lighter and more brittle then compressed charcoal.
It is easy to erase and to shade but is not as dark as compressed charcoal. The removable properties of willow charcoal, through dusting and erasing, are favoured by artists for making preliminary sketches or basic compositions. Unlike compressed charcoal, willow charcoal doesn't use a binding agent which results in clean erasing. Once you have completed an artwork in charcoal it is important to fix your work to prevent smudging. This can be done using a fixative spray.
Please be aware that willow charcoal is a completely natural product made simply from the willow grown on the farms. Therefore the sizes of the charcoal sticks are approximate measurements, one end of the charcoal stick will differ in size to the other end. Look very carefully at a stick of willow charcoal and you will see the marks where the leaves have been removed from the willow stick and also the soft central pith at the core of the stick.