Ok, so the heroquest zombie was given a lick of all equal parts... 2 drops of ink, pledge, water and thinner medium. its a fairly dark effect.
I then added another two drops of pledge and water to the mixture, so 1 part ink and thinner medium, and 2 parts pledge and water. I inked the remains of the heroquest skeleton with it, and you can hopefully see how it slides off the high points more leaving the high parts less inky while still black lining the crevices...