A number of significant innovations in the field of writing instruments comes from the KOH-I-NOOR HARDTMUTH factory. For example, the production of graphite and clay pencil lead, patented as early as 1802, the principle of machine-made pencils or division of graphite pencils into individual grades 8B-10H, according to the hardness of the lead, which were soon taken over by other manufacturers as a global standard.
