Sash windows are beautiful and need some maintenance. You need to keep your sash cords in perfect working conditions. Tru Guard's natural cotton made sash cord is durable and can hold a lot of weight. This is ensured by the outer braid which is 100% polished cotton while the core is synthetic for increased strength. Tru-Guard's cotton rope is rot and mildew resistant. Ľ'' inch thick and 50 feet long, you can use it as a clothesline as the clips don't slide easily or for any other purpose both at home and at work.