it's not graphite, they just call it soft carbon but I'm not sure what the binder is — something, obviously or it would just disintegrate. I highly recommend them — I found them on an art supplies website for £7 for a pack of 6 and thought I'd give them a go. Drawing with them gives you blacks like charcoal but they feel more waxy, and then when you apply the water, it's a wow moment. I see they are on Amazon (but more expensive)