Roller blinds are a type of window treatment that allows you to hang a sheet of fabric and can retract into a tension bar mounted at the top of the window frame. Roller blinds can be translucent and let in a lot of light, or they can be opaque and block light, like blackout blinds. Blackout blinds can get expensive, but if you already have a sheer roller blind, you can transform it into a blackout blind by adding a light-blocking layer right onto the fabric.
Remove the blind from the mounting brackets. Pull the metal tips on each end out toward you from the grooves of the mounting brackets. They should pop out with a little pressure. Place the blind on the floor, fully extended or unrolled. Make sure the street side of the blind is facing up.
Measure the complete length of the blind, from the left, center and right. Write the three measurements down. Measure the width from the top, center and bottom. Write those numbers down as well. Choose the largest measurement from the length and width as your final measurements.
Cut fabric contact paper to fit the measurements. Peel the backing from the bottom corner of the contact paper and press it onto the fabric of the blind. Starting from the bottom corner, use a dry sponge to press any air bubbles out. Peel the backing off a little section at a time, pressing out air bubbles as you go. Continue until the entire sheet sticks to the roller blind.
Trim any areas where the contact paper extends further than the edges of the roller blind fabric.
Roll the blind up tightly. Replace it on the window frame with the contact paper facing the window. Pull and release the roller blind several times to reset the tension in the roller.