I have a sliding glass door in my bedroom and have cellular vertical blinds mounted on the outside of the frame. Just got them installed and now I'm noticing that it's much brighter in the morning than with my old verticals. Looking for something to darken the room. Each glass door is 33" wide and 74" high (2). Thanks.
Answer
The reason why your room is brighter is because the cellular verticals are light filtering meaning that it lets light in. Your old verticals might have been made of PVC which is room darkening.
However there is a solution for you. You can get room darkening inserts. These are put into the pockets of the cellular shades to make them room darkening.