You can find suitable flag cases for sale here

This 12"x18" US flag features printed stars and stripes and is finished with a strong polyester canvas header

Made in the USA

which allows wind to pass through it lessening the strain on the material

Polyester bunting is a heavy-weight material with an open weave for windier applications

5x8 American Outdoor Sewn Polyester Flag 6x10 You can find suitable flagThis 5'x8' Outdoor American Flag is made from heavy duty Polyester material with fully sewn stripes and embroidered stars. Finished with a sturdy polyester header and brass grommets for easy attachment to most flagpoles. Heavier than nylon, this material also has an open weave which allows wind to pass through it, making it more appropriate for flagpoles in windier areas. Made in the USA.