Degrees of Pencils. In manufacturing a pencil, clay and graphite are mixed in varying proportions to produce the various degrees. More graphite means a Blacker result. More clay means a Harder line. The degrees vary from 9B which gives the softest, blackest line to 9H, very hard but paler in colour. HB is half way with 50-50 clay and graphite. The Fine pencil was made as a smooth writing pencil and was popular with shorthand secretaries in the days before computers!
