A few days ago i ordered some special pencils. They are from General Pencil Company this is a copy from there page.

GENERAL'S® CARBON SKETCH™ PENCIL

This fine art pencil has a unique formula combining the smoothness of graphite with the deep rich blacks of charcoal. It lays down smooth, strong, jet-black lines for sketching, drawing, or layout. Perfect when used alone, it can also be combined with charcoal or graphite for a variety of effects. Available by the dozen or in blisterpacks of 2   I have used these once on my piece "Tiger Lily at Night" which can be found on my website or on my facebook page. When i used then the first time I was looking for a nice deep balck coverage for the background of the piece, and i got everything i wanted and more. The Coverage was fast and even, the carbon layed down very smooth and was easy to use. I love them so much i ordered 12 more.