I have had excellent success with cork sheets that are used for lining drawers (don't laugh). The profile is approximately 3/32" to 1/8" thick (roughly N gauge thickness) and comes in a large roll. The down side is that you have to cut for curves, but I simply placed the sheet under the curved track section and then traced the curve onto the cork. It does come with a adhesive backing, but I used an adhesive caulk to keep it in place. I purchased it at Home Depot and is great for yards and siding where you want a lower profile roadbed.