How to Sew Box-Edge Cushions
Turn an ordinary bench or window seat into a comfortable resting spot with a professional-looking box-edge cushion. A box-edge cushion has a wide panel (called a gusset) between the top and bottom of the cushion to accommodate a piece of foam, which results in a thick, comfy, and tailored cushion. It is a versatile design that can be used for both seat cushions and against a backrest.
The instructions below are for an 18x24x6-inch cushion, but you can adjust the measurements for custom window seat cushions or bench seat cushions.
What You'll Need:
1 yard of decorator fabric (52/54-inches wide)
1-1/4 yards of fleece
1-1/4 yards of extra-loft batting
1 17x23x5-inch piece of high-density foam
Upholstery or carpet thread
Heavy-duty spray adhesive
Hand-sewing needle and buttons
Quantities specified are for 52/54-inch-wide decorator fabrics. All measurements include 1/2" seam allowances unless otherwise noted. Sew with right sides together unless otherwise stated.
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Step 1: Cut the Materials
To make the best use of your fabrics, cut the pieces in the order that follows.
From extra-loft batting, cut two 17x23-inch rectangles for the cushion top and bottom, and cut one 5x84-inch rectangle for the cushion gusset.
From decorator fabric and fleece, cut two 19x25-inch rectangles for the cushion top and bottom, and cut one 7x88-inch rectangle for the cushion gusset.
Step 2: Prepare the Foam and Fabric
Use heavy-duty spray adhesive to glue the extra-loft batting to the corresponding sides of each high-density foam piece. Line each decorator fabric piece with corresponding fleece piece; baste each pair together.
Step 3: Assemble the Cushion
Sew the fleece-lined gusset rectangle to the cushion top rectangle; clip the corners as necessary and turn under the raw ends. Repeat by sewing the opposite edge of the gusset rectangle to the cushion bottom rectangle. Leave a large opening; turn to the right side.
Insert the batting-covered foam shape into the cushion cover. Hand-sew the opening closed.
Step 4: Finish the Corners
Give each corner of your box-edge cushion a little extra polish by adding a seam. Along each side seam, flatten the edge by pushing the batting-covered foam shape away from the seam; pin, like you are making a hem. Using a long running stitch and upholstery or carpet thread, tuft the edge through both adjacent sides.
Step 5: Tuft the Cushion
Using a fabric pen, make matching marks for the placement of four buttons on both sides of the cushion. Using upholstery thread and a needle, hand-sew the buttons onto the cushion.
Now that you’ve learned how to make your own cushions, give these upholstery projects a go.
