Re: Inflatable personal PFDs material or fabric
n00b, typically a pfd is made from a welded polyurethane bladder, with a nylon shell over it. The art of welding your own urethane bladde should be beyond most home craftsmen. I suppose you could make a lightweight one out of calendared nylon, which has a light urethane coating calendared into one side of it to make it waterproof, but those materials ALWAYS break down, the only question is whether it will take five years, or ten.
The only way I'd try to make a pfd would be using conventional closed-cell foam as a conventional floatation jacket. Inflateable? No way. Not unless you're going to buy the urethane and the right tools for plastic welding. (Including welding in the inflator and overpressure relief.)