Grafube Grafcube Graphite Sticks 10 & 15 mm, are made of a highly concentrated blend of carbon The cubed stick, can be tooled to create textured lines, and will allows you to create lines that are thick or extra fine. Use flat to cover large areas or on its edge to create defined, thin lines.

Caran D'Ache Grafcube square sticks 10mm

Also in RGB is the well known red, green blue coding system and these Grafcube graphite sticks have been created to add subtle tones in your artwork.  When you apply dry the Grafcube's retain the original graphite properties, apply water and the subtle tones are revealed..