How to make a gym bag (drawstring backpack)

1. Materials & tools

Materials (gym-clothes size)

• Fabric (nylon, cotton oxford or sheeting) — about 110 cm wide × 50 cm
• Acrylic cord (5–6 mm) — about 2 m (use two cords)

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” → “Gym bag (drawstring backpack)” from the tabs at the top.
2. Enter the size
   Enter the finished width, height and the casing drop. Presets fit gym clothes.
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. Fold and cut
   Fold the fabric right sides together and cut the body as one piece with the base on the fold.
2. Mark the notches
   Mark the bottom-corner notches (where the cord loops go).
3. Finish the edges
   Zigzag or serge the side edges.

4. Sewing

4-1. Make the cord loops (for backpack use)

1. Make two small loops from fabric or cord and baste them at the two bottom corners.

4-2. Sew the sides

1. Sew both sides from below the drawstring opening (dashed line) down to the base.
2. Leave the casing opening unsewn and finish those seam allowances neatly.

4-3. Make the drawstring casing

1. Fold the top under by the seam allowance, then by the casing drop, and topstitch all around.

4-4. Thread the cords

1. Thread one cord from each side and tie each into a loop.
2. For backpack use, pass the cord ends through the bottom loops and knot.

5. Tips & variations

• Water-resistant: nylon makes a light, wipeable bag.
• Reinforce corners: backstitch where the cords pull at the base.
• Lined version: add a lining for a tidier inside.