Iron is necessary to them anyway at each building. It's just a fabric background, no paper. In sum, he delivers what it promises and is washable. So great for outdoor etc. or soil-background (there where it goes sometimes dirty) It could be even a tick dense (opaque). But that's a matter of taste ...
Conclusion: If you're looking for just a mobile Portrait background, should seriously consider: A thick clamping sheet clamped on a normal Hinterrgund system is also washable and does not wrinkle! (:-) It is indeed curious)