_Charcoal._ You can't draw, you paint with it.
_Pencil._ It is always touch and go whether I can manage it even now.
Sometimes knots will come in it, and I never can get them out--I mean
little black specks. If I have once india-rubbered it, it doesn't make a
good drawing. I look on a perfectly successful drawing as one built
upon a groundwork of clear lines till it is finished. It's the same kind
of thing with red chalk--it mustn't be taken out: rubbing with the
finger is all right. In fact you don't succeed with any process until
you find out how you may knock it about and in what way you must be
careful. Slowly built-up texture in oil-painting gives you the best
chance of changing without damage when it is necessary.
_Burne-Jones._