If you prefer the sheer curtain in front – Place the blackout curtain furthest back and a thinner one in front. Regardless of which curtain you choose, make sure that the ‘inner’ one goes as close to the window as possible and extends a good distance to the sides, outside the window frame. This will make it as dark as possible. If you enjoy waking up when the sun rises, you should, of course, choose a thinner curtain that allows a lot of light in.