I made some flags for a motorcycle club. I used rip-stop nylon to embroider the designs on. Sewed 2 flags together & added the pole sleeve. I made binding from rip-stop nylon & bound the other 3 edges. That was back in 2008. They are still using them. Seams were 1/2 inch & I double stitched the binding & did a X/box stitch on the corners. If using Sunbrella I think you need to cut it with a hot knife.