Marks such as "2B" are because pencils are divided into different specifications according to the proportion of graphite and clay, and the graphite content in the label 1-6h is very small, so the hardness is high. The larger the pen medium labeled H, the smaller the graphite content and the shallower the handwriting. On the contrary, the larger the pen medium marked with B, the greater the graphite content, and the darker and softer the handwriting. Clay is added to pencils to reduce graphite content and achieve distinction.

Therefore, soft lead pencils refer to pencils with high stone content, soft pens and dark handwriting.

Hope to adopt, O(∩_∩)O Thank you!