I printed a glyph off the internet. Then, I cut only partly into the skin. I scraped that off, then cut a line into the center of the scraped off part, so more light could get through. It was very delicate work. I couldn't cut all the way through, that would just be impossible to do that and get the level of detail. So scraping off the top layer does the trick. Cutting a line into the center of that just makes it look better.