Notice the difference in the color of the padding in the picture. It’s the same original padding it hasn’t been replaced some of the padding where it was covered for many years with a waterbed and carpet seaming tape is much lighter in color, closer to its original color. Where the padding was exposed to environmental factors it has aged it’s darker in color it scratch year the texture of it is scratched here as well. So what causes this aging? My theories are some of the main factors are UV light even though it’s under the carpet exposure to UV light and breaking down the latex glues in the back of the carpet.