How to make a shirt

1. Materials & tools

Materials (men's M)

• Main fabric (oxford, broadcloth or linen) — about 110 cm wide × 200 cm (44 × 79 in)
• Lightweight fusible interfacing — for the collar and front bands
• Buttons (1–1.3 cm / ½ in) — 7–8
• Sewing thread to match

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” → “Shirt” from the tabs at the top.
2. Enter the size
   Enter bust, length, shoulder width, sleeve length, cuff width, neck width and the front overlap. Presets cover women's M, men's M/L and a short-sleeved version.
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 (on the fold), the fronts, the sleeves and the collar. The front pieces already include the button band allowance.
2. Cut
   Cut one back, two fronts, two sleeves and two collar pieces.
3. Apply interfacing
   Fuse interfacing to one collar piece and to the front band area.
4. Finish the edges
   Zigzag or serge the shoulder, side and underarm allowances.

4. Sewing

4-1. Finish the front edges

1. Turn each front edge under twice by the overlap width and stitch. Press hard before stitching so both sides come out the same width.
2. Always do this first — it is impossible once the collar is attached.

4-2. Shoulders and sleeves

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 sleeve into the armhole while everything is still flat.
3. The sleeve head is slightly longer than the armhole. Spread that ease across the top of the cap rather than letting it bunch in one spot.

4-3. Make and attach the collar

1. Sew the collar pieces right sides together, leaving the lower edge open. Trim the corners, turn and press.
2. Sandwich the neckline between the collar layers and sew around, lining the collar ends up with the folded front edges.
3. Clip the neckline curve every 5 mm (¼ in).

4-4. Sides, cuffs and buttons

1. Sew from the cuff, along the underarm and down the side hem in one continuous line, matching the underarm seams.
2. Turn the cuffs and hem under twice and stitch. A curved shirt hem is easier if you stitch a guideline first and press to it.
3. Work buttonholes on the right front, sew buttons on the left, evenly spaced from just under the collar to the hem.

✏️ Sew a test buttonhole on a scrap of the same fabric with the same interfacing. The right length is the button diameter plus the button thickness — a millimetre short and it will not do up.

5. Tips & variations

• Short sleeves: the short-sleeve preset uses the same body, so you can make both from one pattern.
• Straight or curved hem: straight to wear out, curved to tuck in.
• Interface the band: it is tempting to skip, but an uninterfaced button band ripples after a few washes.