The answer is that "It smears effortlessly, because it can make in excess of two tones and individuals utilize it to make light and shade better."
Numerous things can be utilized to make illustrations or drawings. Pencils, pastels, markers, much finger smudges can be utilized. They all have restrictions, however, similar to charcoal.
Charcoal is a restricted illustration medium on the grounds that there's solitary so much you can do with it. You can't eradicate it, and you can just do highly contrasting illustrations with it. Furthermore, it's muddled. One incidental swipe and there's a major spread amidst the illustration.