The phrase “room darkening” must mean different things to different people based on the 4 & 5 star ratings by others. These blinds are no better than the cheapest blinds that you can find at discount stores. The clip that holds the blinds up didn’t work for me. I tried everything I could do to get the clip on the blind but it would not snap on. I tried with the clip not attached to the window just to see if there was anything wrong with how I positioned the clip on the frame that was preventing it from closing. That was not the problem. Returning the product.