A Roman shade, one of the most economical of all window coverings, provides excellent insulation and light protection with minimal fabric. You can add blackout lining to an existing shade by following a few guidelines and taking some careful measurements. A ready-made Roman shade can then be transformed into a blackout shade, making it suitable for use as a room-darkening window covering.
Lay the blind flat on the work surface with the right side to the table.
Measure the width of the blind. Subtract 1/2 inch from the width and add 2 inches for the cut width of the blackout fabric.
Measure the length of the blind from the top of the bottom hem to the top of the blind's headrail. Add 2 inches to this measurement for the cut length of the blackout fabric.
Cut the blackout fabric to these measurements. Blackout fabric has a rough side and a smooth side. The rough side is the right side and will face the street when the shade is finished. (Use "Rough to the Road" will help you remember.) Turn each outside edge under 1 inch and sew in place. Turn the bottom hem up 1 1/2 inches and sew in place.
Place the blackout lining on the shade, wrong side of the lining to the corded side of the blind. Align the bottom of the lining hem to the top of the shade hem. Hold the lining in position with strips of painters tape, positioned perpendicular to the hems.
Feel the position of the rings on the shade through the blackout. Hand-stitch through the blackout lining to the ring, through the ring and back up to the right side of the blackout lining. Make two passes with the thread, tie it off and cut. Sew the lining to all the rings. This stitching is what holds the lining to the shade while allowing the draw cords to move freely in the rings.
Position double-faced fabric tape across the top edge of the blackout panel and adhere the panel to the edge of the blind's headrail facing the window. Remove the tape holding the bottom hem in place. The bottom edge of the lining hangs free from the shade.