Unfortunately, nylon webbing is not resistant to UV radiation. There are some companies where you can order polyester webbing by the meter, such as 50 meters from this website:
https://polimex.net/en/store/product/857-leash-webbing, but it doesn't have any pattern. At Dario, you can design the webbing yourself through their design service and place an order, but it starts at 100 meters:
https://dario-nadruki.com/en/offer/webbings/leash-webbing-for-animals/.
