These drapes replaced some that claimed to block 97% of light (and didn't).  I didn't expect much light-blocking on nights with snow on the ground, a full moon, and neighbors' LED yard lights blazing.  Was I ever wrong!  These high tech drapes are amazing.  Not only do they block all the above at one time, they've provided some amount of thermal protection from polar winds blasting at the window.  The fabric is rich.  I used the garnet color to liven up a dull room.  It definitely worked.  The only downside would be for renters who have restrictions on outside-facing colors.  The outward-facing color is the same as the drape as there is no separate lining.  The other downside is a limited color selection.  I'd love to have more color choices.