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 12 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