How to make a pleated mask

1. Materials & tools

Materials (one mask)

• Outer fabric (double gauze or sheeting) — about 20 cm (8 in) square
• Lining (soft double gauze) — about the same
• Mask elastic — about 30 cm (12 in), two pieces

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” → “Pleated mask” from the tabs at the top.
2. Enter the size
   Enter the width (unfolded) and height. Presets cover adult and child 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 2
   Cut one outer and one lining from the pattern.
2. Mark the pleats
   Mark the dashed pleat folds at the edges so they're easy to fold later.

4. Sewing

4-1. Sew outer and lining

1. Place the outer and lining right sides together and sew the top and bottom (long) edges.
2. Turn right side out and topstitch along the top and bottom.

4-2. Fold the pleats

1. Fold the three pleats in the same direction (downward) using the marks, and pin.
2. Baste the left and right edges to hold the pleats.

4-3. Make the elastic casings

1. Fold each side edge under twice and stitch to form a channel.
2. Thread the elastic through, tie the ends, and hide the knot inside the casing.

5. Tips & variations

• Nose fit: insert a nose wire in the top edge before topstitching.
• Filter pocket: leave a gap in the lining seam to insert a filter.
• Adjustable: use adjustable cord stoppers on the elastic.