How to Cover Your Long Couch

Measure the height of your sofa from the highest area that needs to be covered to the lowest area that needs to be covered. Measure the width from the farthest outside point of one side to the farthest outside point of the other side. Multiply the width measurement by 4 and the height measurement by 2 and add these together, then divide by 36.

Take the number you calculated in Step 1 and purchase this many square yards of both fabric and muslin. Round up, not down, when necessary. Purchase extra fabric to make accent pillows, if you wish.

Lay the muslin fabric over the sofa. Begin at the sofa back and let the muslin hang down as far as the slipcover will, plus 2 inches. Let the muslin drape naturally down the front of the sofa and over the arms; examine the ends and make sure they are even and as long everywhere as the cover needs to be plus 2 inches.

Pin the muslin with straight pins to show where seams will go. Pin between the back and the seat, along the top, between the seat and the front, and along the separation of each arm and the body of the sofa. Draw on the fabric with chalk to show where cuts and trims need to be made.

Remove the muslin carefully without unpinning it. Cut the muslin where necessary to resize it, using sharp scissors. Cut the muslin into large pieces to use as a pattern: one for the back, one for the back of the seat, one for the seat, one of the front and one apiece for the arms.

Wash and dry the slipcover fabric with mild detergent. Lay the fabric face down on a flat surface and smooth it out. Lay the muslin pattern pieces onto the fabric and pin them in place; cut around the muslin pieces to create matching pieces from the fabric.

Take out the pins, and remove and discard the muslin pieces. Pin the pieces of the slipcover together wrong-side-out and drape the result over the sofa to test the size (don't worry, the finished cover will be right-side-out). Adjust any pins where necessary for a proper fit.

Remove the slipcover and sew it together with a sewing machine. Slide out the pins as you sew to prevent damage to your machine. Turn the slipcover fully right-side-out and place it onto your sofa.