Well my wife came across some fabric at Walmart. I've heard tales of silnylon available for 1.50 a yard on occaision. What hallmarks would this grey ripstop nylon fabric have if it were really silnylon? It's very lightweight and very slippery. I can't detect a "rubbery" side to it. she did attempt to force fluid thru the fabric by hand and wasn't successful. Did she manage to find some of the elusive walmart silnylon remants? any help appreciated.