I am in awe ! I have never owned a set of curtains like this. My living room has this monster sized picture window. When I removed the old curtains from this window that someone else purchased and the weather got cold , it REALLY got cold in that room.. It was at least 20 degree difference in that room in compared to the rest of the house.. I could feel the difference as soon as these curtains went up.. By the next morning the temp in that room was aligned with the rest of the house. When I got home from work today I had to open the big window curtains because it was pitch black in there and I have 4 plants in that room as well.. So yeah, these curtains do their job.... I am VERY pleased with these curtains.