These triple weave curtains use blackout yarn technology which is made up of 3 layers woven together, with black yarn used in the middle layer to give 70%+ light blackout. Creating a dark, relaxing environment for sleep as well as privacy. With a grommet top design, you can easily hang them up with your curtain rod, giving your windows a stylish look. TIP:For the best fullness, your curtain total width should be 2-3 times your window width. For best results 280cm would suit windows around 90cm - 140cm.