2.5 mm vegetable tanned leather on top with inlays of black Astrakhan leather which I purchased some years ago from an old man. It has very tight natural wrinkles and as far as I know it is no longer available on the market today. I have never seen any for sale since.
The guitar strap is hand stitched throughout with saddlery grade wax thread and it is lined with pig skin leather. The buckle is covered with kangaroo leather.