A good blackout curtain has to block out the light.
The fabric used for blackout curtains makes all the difference: our dim-out and blackout fabrics are all weaved and textile. A black yarn is inserted in the middle of the two sides of the fabric and the blackout effect (between 90 and 100%) depends on the color and the structure of the fabric. This is why we have categorized all curtains and their performances.
Like every curtain, a our blackout curtain fabric will also help to insulate the room to a certain degree.