Take note of the word parted. Beyond the myriad practical aspects, window treatments, from simple to elaborate, offer us moments of communion, as human hands—whether your own or those of Lady Dudley’s housekeeper—adjust them at will. There are aural pleasures too, from the clicking of curtain rings to the swish of fabric to the creak of shutters to the whir of roller blinds. Literally, the beauty of geometric blackout curtain is an open-and-shut case.