The TQC Pencil Hardness Test according Wolff Wilborn provides in a simple method to test the scratch hardness of coatings. In this test, pencils in a range of 6B to 8H hardness-grade are used. The pencil is moved scratching over the surface under a 45° angle with a constant pressure. Then an optical assessment is carried out to see which pencil hardness damages the surface. Delivered with a set of 20 Koh-i-noor pencils and a pencil sharpener.