Blackout curtains are woven with premium quality blackout yarn on the back to block out 100% sunlight. It will make rooms 10 degrees cooler in summer or warmer in winter. You deserve amazing sleep, even in Alaskan summers with 22 hours of sunlight. Also, the curtains are made of metallic fabric which gives a rich feel and look. They match perfectly with any decor for a bedroom, living room, boys' room, girls' room, kids' room, patio, and sliding doors.