Roller shades naturally have large gaps to the sides of the fabric so these light blocking strips are the perfect solution for maximum light control.
How to stop light coming through blinds.
Purchase blinds that are 1 2 in 1 3 cm or so smaller than the width of your window but long enough to cover the entire window.
Install the blinds before adding anything else to your window like curtains.
Another problem is that these will only work if they are sitting flush with your blinds.
These are extra thick drapes will prevent sunlight from coming through and into your bedroom.
Consider hanging up blackout drapes.
If you have drapes or blinds that let sunlight through them you may want to replace them.
In the window treatment world if the light is coming from the side of the window frame then we call them light gaps.
No light whatsoever will come through the fabric of the drapes therefore keeping your room cooler and less bright.
In other words if you have blinds that are mounted a certain way or your window frame has molding that isn t completely flat from window to outer frame these are useless.
Install blackout blinds that are mounted to your windows.
Next position the bracket first so that your curtains come up at least three inches above the top of your window and at least three inches from the sides of your windows as well and drill your brackets back in.
Keeping your blinds lower may not be the right solution to get relief from this problem.
If your blinds are even 0 5 cm from the strip light will leak through.