- 1). Measure the length and width of the chair seat. Buy a piece of high density foam that's large enough to fit the chair seat, and as thick as you want the cushion.
- 2). Buy a zipper that's at least as long as the back edge of the chair cushion. Many fabric stores sell extra long, heavy duty zippers for cushions and upholstery.
- 3). Cut 2 pieces of outdoor fabric, each about 1 inch longer and 1 inch wider than the piece of foam.
- 4). Cut a strip of outdoor fabric that is 1/2 inch wider than the thickness of the foam, and as long as one long edge and both short edges of the previous piece of outdoor fabric.
- 5). Cut a strip of fabric that's 1 1/2 inches wider than the previous strip, and as long as one long edge of the piece of outdoor fabric. Cut this strip in half lengthwise.
- 6). Pin the 2 narrow strips right sides together, then baste them together along one long edge using a 3/4-inch seam allowance. Make sure to use a heavy duty needle in the sewing machine, if you're using sturdy outdoor fabric.
- 7). Pin the zipper, teeth side down, to the seam allowance. Stitch the zipper tape to the seam allowance only using a zipper foot.
- 8). Topstitch along both sides of the zipper, as close to the teeth as possible, using a zipper foot.
- 9). Use a seam ripper to remove the basting stitches. Remove any loose threads, then unzip the zipper.
- 10
Place the strip of fabric that has the zipper and the other strip of outdoor fabric right sides together, and stitch them together along both short ends. - 11
Place the long edge of the strip around the edges of the one piece of outdoor fabric. Pin the strip to the edge of the fabric, right sides together, then stitch them together using a1/4-inch seam allowance. - 12
Pin the other long edge of the strip to the other piece of outdoor fabric, right sides together. Stitch them together. - 13
Turn the cushion cover right side out. Insert the high density foam into the outdoor fabric cover through the opening in the back. Zip the zipper and place the cushion on the seat of the chair.
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