>>5987238Nitram are regular charcoal, IIRC reputed for their regularity (hardness, hence the ability to have a range of "value").
I'm definitely no charcoal expert, but since nobody answers, maybe the little I know can be profitable: you may be able to get (real) dark with regular charcoal by using a paper that can take a lot of it, as charcoal will easily dust away.
Or, by using compressed charcoal, as the binder will help the dust to stick more. Or, by using fixative in between charcoal layers.
That being said, if you're just starting out, learn to properly use graphite pencils, this will be very profitable.
