Blackout curtains and shades are most often used in bedrooms and media rooms where you want to eliminate any light from entering through the windows.
However, most window coverings are room darkening and not truly blackout because the edge of the window covering creates a “halo effect” of light. If you want to prevent any light from entering to achieve a true blackout effect, you will need to cover the gaps to eliminate the “halo effect” from your windows by using a layered window treatment that combines blackout curtains with either roll shades, cell shades or blinds.
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