Recently I managed to get a box of 6h and 4h minen leads,they are hard as a
rock and when sanded to a chisel shape they could easily cut right through the 220 lb
drawing sheet. Really fun to work with. I have been using them in the lower layers of
the drawing, both for the precise nature of their strokes and their ability to cut up the paper
and so alter the texture of it for later softer layers of pencil. The increased friction then offered
to the pencil tip in later layers allows for a softer deeper shadow where needed.
I'm pretty sure this is what anyone serious about drawing would advise you not to do
but it seems to be working for me.
Thanks for looking :)