BACH is using polyester web only. Polyester webs are strong, abrasion and UV resistant and do not absorb any water. Nylon webs can be of good quality as well but are not so readily available. We do not recommend the use of polypropylene webbing on packs. Compared to polypropylene, polyester is much more resistant against UV-radiation. When buying web for our packs we take special care to make sure, that the webbing qualities are compatible with the buckles we use. It can be quite tricky to make sure, that the web holds the required load. The web must not slip through the buckle but should be easily adjusted at the same time. And not only once but for years to come!