Magic Pen!

As a purveyor of fine pens and writing instruments I normally write with a solid ivory nib dipped in pure melted gold, but as a novelty I might be tempted to try out this pen which writes in some alloy. Kind of looks like a pencil on normal paper but cannot be erased or anything else. I'd be slightly concerned that it would need sharpening after a while of use but hey it'd be worth it.