This is a nice blind that is easy to install and use but and however, as you can see, not really room darkening.  I think it would have to have a material backing to block out the sun more fully which it does not.  My son said that it works well enough for him.  Luckily, this window does not face East so the sun won’t be waking him up in the morning.  If need be I can add a curtain one day.  Hopefully not.