The Comfort Factor: Why Nardi Adirondack Chairs Are a Favorite
https://www.scribd.com/document/991517834/Customizing-Your-Restaurant-Space-with-Grosfillex-Furniture-148122
This material itself is almost always a premium compound, often polypro or structural polyethylene, though major institutional factories treat as proprietary their custom mixes much like cola companies guard their syrup recipes