Well that is an interesting topic. It's made of poly something or other. It was and still is the rain fly to my familys 6 person tent, just modified by me to suit my purposes. That thing is like 20 years old. The red areas leak in the rain like a sieve even with spray on water proofing. It's heavy and takes up far too much room in my pack. But it's mine and I love
it none the less. Besides I do like the colors.