I'm not entirely sure, but I think upholstery backing may be basically the same thing. I stick with the Fluval for a couple of reasons. A box of the stuff will last a long time, isn't very expensive, and I know it's safe for fish, so should be safe for us. As you mentioned, the upholstery backing is usually flame ......ant, and even if it isn't, we don't know what oils etc are on it from the manufacturing process. Fish are very sensitive, much more than we are, so if it's safe for them, then we have some assurance that is shouldn't have harmful coatings for our use.