Then I got out some water soluble crayons and selected all of the colors in the rusty range and began layering them with abandon.
A little water wash and my sketch was coming along nicely. The black was a little light for my taste, so, after trying a few pens, I opted to use a brush and some black acrylic ink to go back in and darken the blackest parts. You have to be resourceful when working with mixed media. When one media doesn't work, try another. Many don't play nice together. In my rock paper scissors unhinged page, the black ink won because it covered the previous layers. Most pens are not up to this challenge.