I was surprised to see they are a fairly thin material and not the old fashioned rubber backed curtains I remember from years ago. I wasn't sure how they would work but thought they came in colors I could use and they were only abour $14/panel (54"W X 84"L). Both bedrooms have nice Levelor honeycomb shades but they're not very good at blocking out the heat of the sun. The master gets hot first thing in the morning from the east sunrise and the spare bedroom faces west so by evening it's pretty warm in there, even with the a/c on.
I put the curtains up and was amazed at how the thin material actually DID seem to block out the sunlight. So, I'm pretty pleased. I even thought the master was dark enough if I wanted to lie down some afternoon and take a nap...well, it's more likely Dane will do that but he doesn't need dark to sleep ~ he can fall asleep in a chair sitting in the back yard! lol But it always seems to me to be cooler if it's darker. And that alone makes it worth the investment.