The top cassette was suspended so I could work with it and get the mounting holes correct. There was less then 1/8 inch error needed in the mounting location. Any error in mounting could cause the shade to bind in either side channel. If it is not perfectly level, the shade can drift to one side or the other when it goes up and down.
There happened to be a stud right on the edge of where the mounting hole needed to be. I wound up getting about 4 different types of blind nuts to find one system that would deploy in that setting.
For the record, this is the type that worked for me:
Looks pretty ugly here with all the black tape, but once I finish the walls, I'll fill the gap between the side channel and the wall so I won't need the black tape.
I am much lower tech. I cut foam core board to fit the openning, and then paint one side of it (usually the outside) flat black. Some times if I need black out in full sunlight I might glue balck construction paper to the front of the foam core. Wrap the edges with black masking tape (b&h sells it).
I am much lower tech. I cut foam core board to fit the openning, and then paint one side of it (usually the outside) flat black. Some times if I need black out in full sunlight I might glue balck construction paper to the front of the foam core. Wrap the edges with black masking tape (b&h sells it).