My poor dog had grown too big to fit comfortably on the front seat of my extended cab truck, and he would fall off the back seat. I don't have rear head rests, so I put the hammock straps through the kiddy car seat loops. The hammock is wide enough so that I can tuck the edges around the upholstery too. The fabric appears to be tough, synthetic, canvas material with a waterproof backing. I live near the coast, so this will come in handy if I have to evacuate, because of a hurricane, with all the dogs.