You need some willow charcoal, a large sheet of buff coloured sugar paper
and paper towels.
You need to crush the charcoal into a powder. Younger hands will find
this harder to do and may need help.
Use the paper towel to rub the charcoal onto the paper. Try to create
a smooth tone all over the paper. Don't rub too much charcoal powder onto
the surface or it will become too dark. There will be a right old mess
in the room here, so put paper down on the tables. Using the paper towels
helps to prevent hands getting too dirty but it won't stop it completely,
so have soap and water ready to wash hands.
Some students want to draw a pencil outline. This is ok but beware they
don't smudge the charcoal ground too much. The student needs to draw the
dark tones on the object.
A good tip here is to squint at the object. This reduces the detail and
improves the look of the tone. They tend to stop looking at the object
and start to make things up, so they need to be constantly reminded to
look at the object.
You can use putty rubbers here, that can be moulded into drawing shapes,
but a cheap rubber also works!
Try to make the students understand that they should rub out the places
where the light is falling on the surface of the object.
Keep drawing with both rubber and charcoal until the drawing is complete.
You need to know when to stop. Don't overwork the drawing. It should look
a little rough. You can fix the drawing with fixative, but cheap hairspray
does the job just as well.
Students tend to try to draw outlines of shapes rather than areas of
tone, so steer them away from outlining gently.