Mitsubishi Hi-Uni Art Set - 10B au 10H : For many pencil lovers, nothing can beat the satisfying feel of a real wooden pencil. Hi-Uni is Uni Mitsubishi's best-selling highest-level wooden pencil line with an incredible selection of 22 hardness grades. The luxurious pencils write in rich, dark, and even lines. Beautiful to write with as well as look at, these wooden pencils will be a marvelous addition to your art tool collection. This set of 22 pencils gives you a delicious taste of all 22 hardness grades ranging from 10B to 10H. Imagine the extensive variety of shades and lines you will be able to draw with this set. The pencils come unsharpened, in a reusable aluminum case. About pencil hardness grades: A greater percentage of clay results in a harder pencil lead, and lead is graded by hardness. Pencils graded H, F, HB and B are of average hardness. Pencils ranging from 2B to 10B are softer and are used for sketching, while 2H to 10H pencils are harder than average. A common American #2 pencil is equivalent to an HB pencil. These are the lead grades from hardest to softest: 10H | 9H | 8H | 7H | 6H | 5H | 4H | 3H | 2H | H | F | HB | B | 2B | 3B | 4B | 5B | 6B | 7B | 8B | 9B | 10B. The harder the pencil the lighter the mark, and the softer B-grade leads tend to create darker colors and smear easily.