The Artline sketch pencil with a grade of 10B features an extremely soft lead, making it ideal for creating very dark and expressive lines, as well as for shading and sketching. The "10B" grade indicates a very soft lead, which is often favored by artists for its ability to produce rich, dark lines and tones. This grade is perfect for achieving dramatic contrasts and adding depth to drawings. Artline sketch pencils are known for their quality and are popular among artists and designers.