Graphite pencils are made of the highest quality Cumberland graphite and the purest clays to produce a smooth texture. Non-toxic. The Sketching Set contains a complete selection of soft graphite (9B to H). This 24-piece graphite pencil set Includes: two each of grades HB, 2B, 4B and 2H; and one each of the remaining sixteen grades (from 9B to 9H). The convenient tin keeps the pencils orderly for rapid selection. The Design Set contains twelve degrees with a majority of soft graphite (6B through 4H). The Technical Set contains twelve degrees with a majority of hard graphite (B through 9H).