nostr:npub1rwast7q4z8skpycsz8epd3jyvgjxhe0uf7ljf93sxvg9qtk9x4vqhyger6

Hmm. You might want to get a flag suitable for the US military - it would be made to be durable under a wide variety of conditions.

Here is one company

https://annin.com/products/military-flags/

with a link to where to buy one.

For the material - it looks like they use 70% polyester and 30% cotton according to this page

https://view.publitas.com/p222-2684/annin-2023-commercial-catalog/page/11

You could also ask the flag company what they recommend as well (if independent).