Designed for students and demanding artists in search of deep, rich black tones, these charcoal sticks are smooth, blend easily and provide a diverse range of tonal values. Drawing instructors make Nitram a must for their students because it will not crumble or skip when used expressively unlike vine or willow charcoal sticks. Nitram charcoal erases well and is easier to work than other charcoal brands. Grade HB (medium) is ideal for homogenizing tones and retaining tonal detail. Details: Black 0.25" x 6" (0.6cm x 15.24cm) stick size 5 sticks Grade HB (medium) Breakage-resistant Square shape makes the stick easier to grip