The width of the grade scale is the difference. Building tone needs several steps between light and dark, and a three pencil school set cannot get there however carefully it is used. Harder grades hold a point for construction lines; softer ones lay dark tone and smudge under a hand. Paper tooth matters as much. See drawing pencils, sketch pencils and art paper.

Artist pencils in a wooden case on a bright studio desk with sketchbooks, drawing tools, artwork and latte art coffee.
Artist Pencils for Drawing and Illustration

Artist pencils for sketching, shading and illustration. Shop creative pencils for students and professional artists.