How to Make a Bedroom Completely Dark
By Patricio Marquez · October 6, 2026
Blackout fabric blocks light, but a lot of people install blackout shades and still wake up to bright lines around the window. The fabric isn't the problem; the gaps are. Here's how to get a bedroom truly dark for kids, shift workers, and light sleepers.
Why light still gets in
An inside-mounted shade needs a small gap on each side so it can roll freely. Sunlight comes through those gaps, plus over the top of the roll and under the bottom bar.
Fix 1: side channels
Side channels are slim tracks the fabric slides into. They close the side gaps and are the most effective single upgrade for a blackout roller shade.
Fix 2: outside mount
Mounting the shade outside the frame lets it overlap the window on all sides, which cuts edge light a lot, especially on shallow frames.
Fix 3: layer with blackout draperies
A blackout shade plus blackout-lined draperies mounted wide and high is the most reliable way to get a room close to fully dark. Ceiling-mounted ripplefold with returns to the wall works especially well.
Fix 4: dual shades
A dual day and night shade gives you soft light in the morning and blackout at night from one compact system.
Best picks for nurseries
Use cordless or motorized blackout shades so there are no cords in the room, and add side channels or blackout draperies for naps in bright afternoons.
Frequently asked questions
What's the difference between blackout and room darkening?
Blackout blocks light through the fabric completely. Room darkening blocks most of it but lets a little glow through.
Do blackout cellular shades work?
Yes. Blackout cellular shades are a great option and add insulation too.