Digital BW, The Print

Go to the art supply store and buy several soft lead pencils. 
Brand name is Staedtler Mars Lumograph 100. I have them in 
"HB", "2B", "4B", and "6B". Each one is a slightly more soft lead. 
They work fine on papers like Museo, ESFA, Somerset 505, and 
PhotoRag. Just test them out on the trim pieces; you'll know the 
one that suits you immediately.

All of these are softer lead than even the standard #2 pencil lead.

MT, http://www.marktucker.com/