In another thread, I showed a pen made from stabilized chechen burl, where you could some brass showing through. I did work on that blank and got it better, but not good enough. I had extra tubes so I just started over but this time I colored the tube black with my preferred method, a black Sharpie. No mess, doesn't add thickness to the tube, no waiting for paint to dry, and most importantly, it works. This blank was full of cracks and voids, like the first one. Took a lot of patience and CA, but in the end it turned out wonderfully. Here's the result.