I have not scientifically researched this product. My understanding is that Schoeller is a brand name, like Gore-tex, that was invented in, and is marketed from, Switzerland. Anyway, it is stretchy and breathable, like super heavy duty Lycra. Yet it is tough, abrasion and wind resistant, and astoundingly water repellant.
I recently shopped for a pair of mid-weight pants and could not find the fabric that I was looking for heavy duty nylon or polyester designed like blue jeans. REI had a sale on a somewhat sissy-looking stretchy product with zippered pockets, kind of like high fashion ski pants. The price was discounted heavily, so I got them. They are made of Schoeller.
They are now my favorite pants. They are light and breathable enough to play tennis or road bike. Yet they are tough, wind and water resistant enough to backpack, canoe and downhill ski. The pockets are all zippered for full security, with enough stretch to hold about anything that I stuff in them.
Live and learn. Whenever we stop stretching mentally and physically is when we start shrinking. Life appears to have no happy medium of just getting along...you are either growing, or getting left behind. I was getting left behind on the outdoor fabric front until I discovered Schoeller fabric.