Would these pencils be suitable for drawing under oil paint, and using no fixative? A lot of artists are happy to use charcoal under oil, but recommend again "lead"/graphite pencils, as lines can rise in the paint. Graphite is carbon, but it is of a type that is used as a lubricant. Charcoal is also carbon. So when I saw that Carbon Lead was in the description I wondered if these leads are actually not graphite and would be suitable.
Not all Staedtler pencils are "carbon lead", but a lot are designated that way, so I would guess it is just their way of saying "pencil".