Advantages: rich in layers, can go in-depth, and paint in detail.
The hardness mark of pencil lead core generally uses “H” to indicate a hard pencil, “B” to indicate a soft pencil, “HB” to indicate a pencil with moderate hardness, and “F” to indicate a pencil with a hardness between HB and H.
Arrangement (from soft to hard) 9B, 8B, 7B, 6B, 5B, 4B, 3B, 2B, B, HB, F, H, 2H, 3H, 4H, 5H, 6H, 7H, 8H, 9H, 10H, etc. Hardness level.
