Recently I decided to try to draw and faced with the problem of determining the hardness of the stylus of pencils standing in a pencil case or lying on a table. Designations H, HB, etc. almost never visible. It would seem a trifle, but annoying. You have to constantly pull them out one by one to see the marking and find the right pencil. If they lie on the table, then the probability of visibility of the marking is 1: 3, since there are six faces, and you can only read the symbol (without performing any actions) from two. Round pencils have the same visibility.
I suggest applying a spiral along the pencil axis, the thickness and number of turns of which depend on the hardness of the slate. The harder it is, the thinner the strip and the more coils, because the harder the pencil draws a thinner line and is erased more slowly. The spiral itself is visible regardless of the position of the pencil and the degree of its wear.
