kovuuslyijykyniä
Kovuuslyijykyniä, often referred to as pencil hardness scales, are a standardized system used to denote the hardness of graphite pencils. This system originated in Europe and is widely adopted internationally. The scale ranges from hard (H) to soft (B), with the number preceding the letter indicating the degree of hardness or softness.
The scale begins with 'H' pencils, which are harder and produce lighter, finer lines. These are useful
In the middle of the scale is 'HB', representing a balance between hardness and softness, making it