Prepare the Curtain

• 1). Open the top, side and bottom seams on each curtain panel you wish to line with the blackout lining. If your curtain has pleats at the top only open the hem seam at the lower edge of the header.
  
  
• 2). Measure the length of the curtain fabric to the original fold line. If you have a pleated header only measure from 1/4 inside the seam line to the original fold line. This is your finished length.
  
  
• 3). Measure the width of the curtain fabric to the original side fold lines. This is your finished width.
  
  

Calculate the Blackout Lining

• 1). Choose a blackout lining color which is usually available in white or off-white.
  
  
• 2). Subtract five inches from the finished length of the curtain. This is the length of your blackout lining.
  
  
• 3). Subtract eight inches from your finished width of each curtain panel. This is the width of your blackout lining.
  
  

Assemble

• 1). Cut the blackout lining.
  
  
• 2). Hem the bottom of the blackout lining using a one half inch hem. Turn the hem up 1 1/2 inches and stitch.
  
  
• 3). Lay the blackout lining on the front of the curtain fabric with the right sides together and the top and right edges even. If you have pleated curtains place the top if the lining just under the seam of the header hem.
  
  
• 4). Sew the right edge. Stop sewing just before you reach the blackout lining hem.
  
  
• 5). Line up the left edges of the blackout lining and the curtain fabric. Sew the left side seam. Stop before you reach the blackout lining hem. The fabric will bell which is expected.
  
  
• 6). Press the seam allowances toward the blackout lining.
  
  
• 7). Center the blackout lining on the fabric.
  
  
• 8). Restitch the original seam lines.