Here's a fella I drew on the couch last night using my trusty #2 sable brush and india ink. I've been pretty inspired from seeing an original Jack Davis piece, and decided to emulate the DuoShade shading he used on his original art. Unfortunately I don't have any DuoShade paper, so I just scanned it in and added the lines digitally.
DuoShade paper is treated art board, and by adding a chemical wash you bring out diagonal lines (or dots) to create uniform and reproducible shading for print . There are two chemicals actually, and each brings out a different weight & direction of line shading. With the popularity of computers and colour art, DuoShade has ceased production, but I'm on the hunt to get some to try for real. It looks like great fun!