If you want to sew outdoor cushion covers, there are a few things you need to keep in mind. First, you need to choose a fabric that is durable and can withstand the elements. Second, you need to make sure the seams are sealed so that water cannot get in and ruin the cushion fill. And finally, you need to use a thread that will not rot or mildew in the outdoors.
To start, measure the width and height of your cushion insert. Add 1 inch to each measurement for seam allowances. Cut two pieces of fabric using these dimensions.
Next,Pin the two pieces of cut fabric together with right sides facing each other. Sew around all four sides using a 1/2-inch seam allowance. Leave a 4-inch opening along one side for turning and stuffing the cushion cover later on.
After sewing, trim the corners of the sewn piece to reduce bulk when turning it right side out later on. Then turn the sewn piece right side out through the 4-inch opening that was left earlier. Use a chopstick or similar tool to help push out the corners so they are nice and sharp.
Now it's time to stuff your cushion cover! Place your insert into the cover through the opening, then carefully remove any wrinkles and smooth everything out so that it looks good from all angles.. Once your insert is in place, simply sew up the opening closed using a ladder stitch or blind stitch by hand