How to make a phone shoulder bag

1. Materials & tools

Materials (one bag, standard size)

• Outer (canvas or linen) — about 140 cm wide × 45 cm (the strap is long; piece it if your fabric is narrower)
• Lining (light cotton) — about 30 × 25 cm
• Lightweight fusible interfacing — about 30 × 25 cm
• A magnetic clasp — 1
• Sewing 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 “Bags” → “Phone shoulder bag” from the tabs at the top.
2. Enter the size
   Enter the width, the height, the gusset, the strap length and the flap depth. Presets cover small, standard and large phones.
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. Measure the phone
   Width and thickness, with its case on.
2. Trace the pattern
   Lay the pattern on the wrong side and trace both lines.
3. Cut the pieces
   Two outer, two lining, one strap, and two flap pieces if you want a flap.
4. Transfer the notches
   Mark the strap positions on the top edge.

4. Sewing

4-1. Make the flap

1. Place the two flap pieces right sides together and sew the three lower edges, leaving the top open.
2. Trim the corners diagonally, turn and press.
3. Topstitch round it.

4-2. Sew the body

1. Place the two outer pieces right sides together and sew the sides and base.
2. Pinch the bottom corners and box them.
3. Sew the lining the same way, leaving 6 cm open in the base.

4-3. Baste the strap and flap

1. Fold the strap in four and topstitch.
2. Turn the outer right side out and baste the strap ends at the side notches.
3. Baste the flap to the back top edge, pointing outwards.

4-4. Join outer and lining

1. Drop the outer inside the lining, which stays wrong side out, and sew round the top — strap and flap are caught in.
2. Turn through the gap and close it.
3. Topstitch the top edge and fit the magnetic clasp.

✏️ Decide the strap length with the bag actually on. 120 cm puts it at hip height on an average build, but height changes that a great deal. Try it while the strap is only basted, then sew it in.

5. Tips & variations

• Hands free: for walking, shopping, or being out with a child.
• Magnetic clasp: it opens one-handed, which a button does not.
• Keep the strap wide: narrow straps dig in. A 4 cm strip folded in four is about right.