Graphite Core: The core is made of graphite mixed with clay; the ratio determines hardness.

Hardness Scale:

• H (Hard): Lighter, finer lines; less smudging — good for outlines and technical details.

• HB: Mid-range; balanced darkness and smoothness — versatile for general sketching.

• B (Soft): Darker, softer marks; ideal for expressive shading and tonal work.

• Numbers: Higher numbers (e.g., 6B) are softer and darker, while higher H numbers (e.g., 4H) are harder and lighter.