Not total darkening but sufficient for price

Be aware these do not appear dark grey at all as the manufacturer has labeled on the packaging. These DO have a basketweave print but in blue and black and look dark blue when hung. I was expecting this and am happy with the result because I have a blue-grey sectional that is very difficult to match. Here I have the curtains hung in 2 different parts of our bonus room with the same sectional split against a light grey wall and a dark blue-grey wall for reference.

These are perfect, they match the bedroom colors I was looking for.

I absolutely love these. They go so well in my living room and match the floor and wall color. I highly recommend them.

I like the look and feel of these curtains. They definitely need steamed after hung, due to the wrinkles from folding in shipping. They do block most of the light from outside.