Hello people, I've just layed the main line on my module and it might be smart for me to ask this first before I continue with balasting it completely. I use a small strip of cork, it's 12mm wide and 1,5 mm thick which fits exactly under the rail. (it's Z-scale) When adding ballast I didn't like the small edge it created. That's why I want to eliminate this small edge by adding an extra material so it drops off more smooth and realistic. What kind of material can I use for the yellow part in this picture? Thanks for the help!