How to make a belly warmer

1. Materials & tools

Materials (one warmer, size M)

• Jersey (interlock, rib or wool blend) — about 90 cm wide × 40 cm
• A ballpoint needle (75/11) and stretch thread

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 “Accessories” → “Belly warmer” from the tabs at the top.
2. Enter the size
   Enter the waist, the length, the ease and the turn-back. Presets cover S, M, L and child.
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. Trace the pattern
   Lay the pattern on the wrong side and trace the cutting line. Run the stretchiest direction across the width.
2. Cut the piece
   Cut one.
3. Check the stretch
   Pull the fabric both ways and confirm which stretches more before you place the pattern.

4. Sewing

4-1. Join into a ring

1. Fold right sides together and sew the short edges into a ring.
2. Use a ballpoint needle and a stretch stitch.
3. Rather than pressing the allowance open, press it to one side and topstitch — it sits softer against the skin.

4-2. Turn the edges back

1. Fold the top edge inwards by the turn-back amount and stitch all round.
2. Do the same at the bottom.
3. Use a stretch stitch, or the thread snaps when it is pulled on.

4-3. Finish

1. Turn it inside out and check nothing rubs.
2. Press on a low setting through a cloth, lightly.

✏️ The ease is negative — smaller than the actual measurement. Jersey stretches, so made to the exact measurement it slides down. About 6 cm under the waist measurement stays put without squeezing.

5. Tips & variations

• Stretch runs across: cut the other way and it will not go on. Check before cutting.
• Go longer: covering the lower back as well as the stomach changes how warm it feels.
• Wool for winter: a wool blend for cold weather, cotton interlock for air conditioning.