Best Light Blocker Strips for Blackout Window Blinds & Shades

Enhance your blackout window treatments with light blocker strips — the most effective way to block side light and improve sleep quality.

Light Gaps in Window Shades: The Hidden Problem

If you've installed blackout shades or blackout blinds expecting complete darkness — only to wake up to sunlight sneaking in through the sides — you're not alone. The light-gap issue is one of the most common problems with standard blackout window coverings.

The reason? Most shades and blinds are made slightly narrower than the window frame to allow for smooth operation. But that gap — known as a side light gap — lets in frustrating streaks of light.

This article explains why even the best blackout blinds still let light in — and introduces the simple, effective solution: light blocker strips.

When You Need Complete Darkness, Not Just "Dark-ish"

Sure, sunlight has its moments — like a gentle morning wake-up. But not when:

• Your child’s nap is cut short by sunbeams in the eyes.

• You’re trying to sleep after a night shift and daylight floods your room.

• You’re battling a migraine and even a sliver of light is unbearable.

• You’re trying to create a dark home theater but glare ruins the screen.

Even a tiny light leak from the sides of blackout blinds can feel like a flashlight in your face.

The Truth About Blackout Shades: They Don’t Always Black Out

To be clear: we’re not against blackout blinds — in fact, we love them. They’re far better at light control than sheer, solar, or light-filtering shades. They boost privacy, reduce heat, and improve sleep quality.

But here’s the catch: “blackout” doesn’t mean 100% blackout.

Most blackout shades leave light gaps on the sides and bottom. It’s a design necessity — shades need some clearance to avoid scraping or jamming. The result? Light creeps in where you don’t want it.

How to Block Side Light from Blackout Shades

Enter the light blocker strip — also known as blackout side tracks, light gap blocker, window light blocker, side channels or side light blocking rails. These L-shaped strips are installed along the sides of your window frame, forming a barrier between the shade and the frame to block light leaks.

This is the #1 accessory to turn your regular blackout blinds into true 100% blackout window treatments.

What to Look for in Light Blocking Strips for Windows

When shopping for light blocker strips for window blinds, look for the following features to ensure a perfect fit and long-term performance:

✅ Universal Fit: Choose strips that work with most inside-mount blackout roller shades, cellular shades, zebra blinds, and Roman shades.

✅ L-Shaped Design: The best light blocking strips have a pre-formed L-shape that sits snugly between the window frame and shade.

✅ Black Inside / White Outside Finish:

• Black interior surface absorbs light and enhances blackout effect.

• White exterior is paintable and blends into your window trim.

✅ Durable PVC Material: Strong, lightweight, and warp-resistant. Easy to cut to size using scissors or a utility knife.

✅ Permanent or Removable Options:

• Permanent: Use commercial-grade adhesive for fixed installation.

• Removable: Ideal if you have tilt-in windows or seasonal screens — easy to reapply after cleaning.

✅ Cut-to-Size: Look for strips offered in multiple lengths or easily trimmed to your exact window height.

✅ Flexible Return Policy: A 30-day guarantee that covers you even if you've cut the strips is a must.

✅ Made in China: If local manufacturing matters to you, check product origin.

Installation is Simple – Block Light in Just 20 Minutes

Most light blocker strip kits are designed for DIY installation:

Peel & Stick: Use the included adhesive tape for quick tool-free setup.

Screw-Mounted Option: For added durability in humid or high-traffic environments.

Just clean your window frame, cut the strips to size, and press into place. That’s it — no more annoying light leaks.

Bottom Line: Light Blocker Strips Are the Best Add-On for Blackout Blinds

No matter where you live — urban high-rise, suburban home, or countryside retreat — controlling light in your bedroom is crucial for rest and recovery. Standard blackout shades still allow side light leaks, but installing L-shaped blackout side tracks solves the issue fast.

If you're searching for:

• How to block light from sides of blackout blinds

• Light blockers for window blinds

• 100% blackout window solutions

• Best blackout accessories for shades

Then light blocker strips are your answer.

Sleep Better, Anytime

Whether you work nights, nap during the day, or just want a completely dark space to rest or relax, light blocking strips for blackout blinds are a must-have.

Contact us today or browse our collection to get the true blackout performance you’ve been looking for.