Experience the darkness, silence, and bliss of the Blackout Thermaliner Curtain Panel. The blackout liners have been laboratory-tested to block out over 99 percent of outside light and reduce unwanted noise for a better night's sleep. Pair this energy-saving liner with your existing curtains and immediately start saving on home heating and cooling costs. Thermal curtain liners give you the instant versatility to add more function to your window treatments.