POLYMER LEADS

Composition:

Just like the leads of wood-cased pencils, fine-point pencil leads contain graphite as the colourant ingredient.

Rather than clay (as in pencils) the binding agent is a carbon skeleton ("polymer skeleton"), which renders the leads more elastic.

Therefore, a lead can be substantially thinner than a pencil lead with the same breaking strength.

The raw leads are impregnated with a grease/wax mixture, just like conventional pencil leads.