Black-Out Roller Shades
Black out fabrics do not allow light to shine through and are usually paired with basic roller shades allowing the material to be close to the window so to minimize "light leakage" via the edges. Although inside mount options exist, it is best to mount these shades outside the window frame for maximum effectiveness.
Additional options include cassette or valance rail heads. Blackout Shades with Side Channels can be used to completely block out the light.
Available with cord, chain or motorized controls.