How to make a cushion cover (envelope)

1. Materials & tools

Materials (one cover)

• Outer fabric (cotton, linen or canvas) — about 110 cm wide × 60 cm
• Back fabric (same fabric is fine) — about 110 cm wide × 80 cm
• A cushion insert

Tools

• Sewing machine (or needle and thread)
• Fabric marker or pencil
• Ruler and scissors
• Iron
• Pins or clips

2. Make the pattern (auto-generated in Katagami)

With the Katagami pattern tool, you just enter the finished size and it drafts a seam-allowance-included pattern, tiled to print at actual size on Letter or A4.

1. Open the tool
   Open the pattern tool and choose “Home” → “Cushion cover (envelope)” from the tabs at the top.
2. Enter the size
   Enter the cushion width, height and the back overlap. Presets cover common sizes.
3. Set the seam allowance
   Use the slider at the bottom (beginners: 1.0–1.5 cm / about 3/8–5/8 in).
4. Print
   Press “Print (actual size)”, then in the print dialog set Scale = 100% and turn “Fit to page” OFF. Check the 50 mm calibration box on the first guide sheet with a ruler.

3. Cutting the fabric

1. Cut the front
   Cut 1 front: the cushion width × height plus seam allowance.
2. Cut the back
   Cut 2 backs from the (shorter) back pattern.
3. Finish the opening edges
   Finish all seam-allowance edges, and especially the back opening edges (one short edge of each back piece).

4. Sewing

4-1. Hem the back opening edges

1. Double-fold and press the inner (opening) edge of each back piece.
2. Topstitch about 2 mm from the fold.

4-2. Overlap the back pieces

1. Lay the two back pieces right side up, overlapping the hemmed edges by the overlap amount.
2. Pin, and baste the overlap to make it easier to sew.

4-3. Sew front and back together

1. Lay the front right side down, then the overlapped backs right side up on top (right sides together).
2. Sew all four sides.
3. Trim the corners diagonally to reduce bulk.

4-4. Turn and finish

1. Turn right side out through the back opening.
2. Push the corners out, press, and topstitch the edges if you like. Insert the cushion.

5. Tips & variations

• Snug fit: make the cover ~1 cm smaller than the insert for a plump look.
• Bigger overlap: a larger overlap keeps the insert hidden.
• Piping: add piping in the seam for a tailored finish.