How does shading & blending with Carbon pencils differ from Graphite pencils? From what I've read, carbon pencils give a more matte-like texture than graphite, and are a drier media - similar to charcoal. Graphite can become reflective when photographed and scanned so I'm surprised that carbon pencils aren't more popular.


Do carbon pencils need to be blended differently for a smooth gradation of tone (like willow charcoal does), or is it more similar to graphite shading?
Are carbon pencils messy, or can a precise line be achieved with it?
Are there any disadvantages to drawing with Carbon instead of Graphite?


If it's not too much trouble, imagery for comparison is very welcome!
I find that Carbon Pencils tend to dry out and break easily while I work. If I use carbon, I try buy one which is oil based; they tend to have strong tonal values without the shininess of graphite. You can make a very sharp line with a neatly sharpened pencil. I sometimes wet it with some linseed oil, or saliva, if it looks a bit dry. 

Graphite is used as a lubricant in some industrial processes. So it applies more smoothly but I find the shine is annoying at times. You should consider the grade of your graphite as well. The ratio of graphite mixed with clay will affect the shininess in some pencil brands. The Staedtler Black Red 7B is an example that doesn't have a shiny gloss compared to other brands.