I did another inking of my sketch. This time I only used a brush and black ink. Again, the tone was added in Photoshop.
I am trying to emulate digitally the look of the old Craftint or Duoshade paper. It was, or may still be, a heavy paper with one or two invisible tone patterns imprinted onto it. The dark line or dot patterns appeared by the application of a developer - a separate chemical for either the light or the dark tone. Cartoonists would use dip pens or brushes to apply the fluid.
John Severin is the master of this technique.