How to make a sling bag (crossbody)

1. Materials & tools

Materials (standard size)

• Main fabric (nylon or canvas) — about 70 × 60 cm (28 × 24 in)
• Lining fabric — the same amount
• Fusible interfacing — for the main fabric
• Webbing or a self-fabric strap — the length you chose
• Zip — to the opening width
• A slider for adjustment — 1

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 “Bags” → “Sling bag (crossbody)” from the tabs at the top.
2. Enter the size
   Enter the finished width, height, gusset, lower corner radius, strap length and cut width. Presets cover small, standard and large.
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 body including the lower corner radius, the gusset and the strap.
2. Cut
   Cut two body panels and one gusset in main and lining, plus one strap.
3. Apply interfacing
   Fuse interfacing to the main pieces so the bag holds its shape when empty.

4. Sewing

4-1. Make the strap

1. For a self-fabric strap, fold in quarters, press and topstitch both edges. For webbing, cut and seal the ends.
2. Thread the slider on before attaching anything.

4-2. Insert the zip

1. Sandwich the zip between the main fabric and the lining along the opening edge and sew all three layers.
2. Open them away from the zip and topstitch close to the teeth. Repeat on the other side.

4-3. Attach the gusset

1. Match the center of the gusset to the base center of one body panel and pin outward.
2. Sew all the way around, catching the strap ends at the top of each side.
3. Attach the second body panel the same way, remembering to open the zip first so you can turn it.

4-4. Finish

1. Turn through the open zip and shape the bag.
2. Topstitch around the gusset seams if you want a crisper edge.

✏️ Open the zip before you sew the second body panel on. Sew it closed and the bag becomes a sealed pouch with no way to turn it right side out.

5. Tips & variations

• Adjustable strap: a slider lets you wear it high at the chest or low at the hip.
• Wear it forward: pulled round to the front in a crowd, it is far harder to get into.
• Water-repellent fabric: this bag lives outdoors.