Sew a removable box cushion cover

Before you start

Measure the insert without compressing it and record its length, width and thickness. Pre-wash the fabric only if its care instructions allow it, then press it flat. Mark the grain and the direction of any pattern. Choose a seam allowance you can repeat on all panels.

Tools and materials

• Woven furnishing fabric
• Sewing machine and thread
• Tape measure and fabric scissors
• Clips or pins

Step-by-step instructions

1. 1

   Draft the panels from the insert

   For a 45 × 40 × 5 cm insert and 1 cm seams, cut a 47 × 42 cm top and a 7 cm wide band. The band needs 170 cm of finished length around the cushion, plus allowance for the joining seam. Piece shorter strips if needed and keep joins away from corners.

2. 2

   Make the overlapping underside

   Cut two panels across the width of the cover. Allow enough depth for their hemmed edges to overlap by several centimetres. Hem the opening edges, then pin the two pieces together and adjust the overlap until the outside edges match the top panel. Baste the overlap at the ends.

3. 3

   Sew the band to the top

   Join the band into a loop. Mark the four corner positions along the seam line and match them to the top panel. Sew with right sides together, pivoting at each corner with the needle down. Clip into the band’s seam allowance at the corners if it needs help turning, keeping clear of the stitch line.

4. 4

   Sew on the underside

   Match the four corners with the band and keep the overlap flat. Stitch all the way around the outside edge. Trim bulky allowances where needed and turn through the opening.

5. 5

   Turn and fit

   Turn through the overlap and insert the cushion. Work the corners into place and check the opening stays closed under light pressure.

Check the result

Put the cushion on its seat and press lightly in the centre and at each corner. The side band should sit straight, the corners should be filled and the overlap should stay closed. Trim loose threads and check that the insert comes out through the opening without stretching a seam.