How to make a blouson jacket

1. Materials & tools

Materials (size M)

• Main fabric (nylon, twill or denim) — about 110 cm wide × 180 cm (44 × 71 in)
• Ribbing for the hem and cuffs — about 30 × 90 cm (12 × 35 in)
• Separating zip — to the finished body length

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 “Adult clothes” → “Blouson jacket” from the tabs at the top.
2. Enter the size
   Enter bust, length excluding ribbing, shoulder width, sleeve length, hem and cuff ribbing height and ease. Presets cover S, M, L and a relaxed fit.
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
   Trace the back, fronts, sleeves and the two ribbing pieces.
2. Cut
   Cut one back, two fronts, two sleeves, two cuff ribbings and one hem ribbing.
3. Finish the edges
   Serge or zigzag the shoulder, side and underarm allowances.

4. Sewing

4-1. Shoulders, sleeves and sides

1. Sew both shoulder seams and press the allowances open.
2. Match the center of each sleeve head to the shoulder seam and sew the sleeves in.
3. Sew from the cuff along the underarm and down the side in one continuous line.

4-2. Attach the ribbing

1. Sew each cuff ribbing into a loop, fold it in half lengthwise and sew it to the cuff, stretching it to fit.
2. Fold the hem ribbing in half lengthwise and sew it to the hem, stretching evenly. It is shorter than the hem — that is what makes the jacket blouse.

4-3. Insert the zip

1. Sew one side of the separating zip to each front edge. Line the bottom stops up with each other before you start, or one side will finish higher than the other.
2. Turn the neckline under twice and stitch.

✏️ Cut ribbing to about 85% of the edge it goes on. Stretching that shorter piece evenly as you sew is exactly what pulls the hem in and gives a blouson its shape.

5. Tips & variations

• If zips put you off: snaps or hook-and-loop close it just as well. Make it that way first and add a zip to the second one.
• Water-repellent fabric: in coated nylon this becomes a light rain jacket.
• Add pockets: slash pockets caught in the side seams are worth the extra ten minutes.