This is a variation of media courtesy of Octavio Perez.
Step 1: Create a tight sketch
Step 2: Mount a photocopy of the sketch with Matte Medium to Illustration board
Step 3: Score the illustration board where the stiches are with an exact-o.
Step 4: Rub Burnt Umber oil paint into the entire piece
Step 5: Use a solvent (turpenoid) to lift out the light areas
Step 6: Paint into the piece with acrylic, it is best to stay as light as possible with the acrylics because it saves time and it'll let your line work show through nicely.