Blackout blinds are blinds that have a coating on the back of the blind material that prevents all light from the window from entering the room. It may be the case that some brands of blackout blinds are expensive to install in your home's windows. Fortunately, there are companies that sell blackout kits that you can use to turn your old blinds into blackout blinds. With the correct materials, you can black out blinds with minimal work and tools.
Measure the size of your blinds.
Cut a single piece of blackout fabric to the exact measurements of your blinds.
Attach strips of self-adhesive Velcro to the border of the blinds. Make sure that the blinds are tightly closed first.
Attach strips of self-adhesive Velcro around the entire border of the blackout fabric.
Press the blackout fabric into the blinds so that the Velcro from the blinds and the Velcro from the fabric attach to each other. Press down firmly on the border so the blackout fabric rests tightly against the blinds.
If you turn your old blinds into blackout blinds, you will not be able to roll or open your blinds while the blackout fabric is covering the blinds. Your blinds may hang in such a way that you still receive a little light from the sides of the blinds. To fix this problem, consider blacking out the window in front of the blinds, rather than the blinds themselves. Using the same Velcro and blackout fabric method, place the Velcro on the border of the window frame, rather than on the blinds. Then stick the blackout fabric on that border in front of the blinds, blacking out the entire window.