I did a demo of these at an energy fair, which promted the sewing workshops that I now do twice a month. Basically, picture a narrow board on the top of the window casing, with 2 strips hanging down around a rolled up piece of quilted fabric. On the ends of these strips are pieces of velcro. when rolled up, these strips hold the fabric. when fabric is rolled own, you can use 2 strips of wood (sorta like strapping) with spring loaded hinges to hold the window quilt tight agaist the wall. Also, if you make a narrow pocket at the bottm, you slide a thin piece of wood in there to help weight it own. If you have any questions , PM me, as I am leaving for work.