Any form of double layering solves the problem, really. Whether it's double layered at the window, or double layering in discrete locations (windows & eyes), ha

Any form of double layering solves the problem, really. Whether it's double layered at the window, or double layering in discrete locations (windows & eyes), having two distinct solutions with their own strengths and weaknesses can usually resolve edge cases in both. ...this applies to lots of things in IT as well, not just window curtains :-)