With Prang's paper wrapped charcoal pencils, pull the string to remove part of the paper and expose more charcoal -- no sharpener needed. The charcoal comes in three grades: hard, medium or soft. Drawing paper or other toothed papers give best results.Details: Black 6 packs (12 pencils per pack, 72 total pencils) Available in hard, medium, soft grade Soft core Easy pull string for self sharpening AP- and PMA-certified nontoxic Made of select charcoal, finely ground and free of impurities