These images are drawn by me with conte, it’s gritty and chalky but you can mould it with a tortilion or your finger to make it softer. You can get conte in just about any colour and even in conte pencils.
The old masters had sepia or burnt umber and it was usually a sketch only.
I like this medium it has a tone and softness about it, but the substance is gritty and not always easy to use. It’s well worth the effort to give this a go if you like art work.