Thanks for commenting on our post. I prefer to use a blend with some cotton, because you can train cotton to fold easier. Linen and silk are also fun to use but when making a silk roman shade you should use Interlining to prevent the silk from fading and rotting. If your windows have a lot of sun polyester is OK, but it doesn’t always fold as well as other fabrics so I would suggest using interlining or a heavy cotton lining.