How to make a cup bag (gusseted)

1. Materials & tools

Materials (cup / bento size)

• Fabric (cotton oxford or canvas) — about 35 × 50 cm
• Round cord (3–5 mm) — about 50 cm × 2 (both-side draw)
• Bodkin (or a safety pin)

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” → “Cup bag (gusseted)” from the tabs at the top.
2. Enter the size
   Enter the width, height and gusset (base depth). Presets fit a cup or bento.
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 cut and seam lines; align the grain.
2. Cut
   Cut as one piece with the base on the fold. The base corners show gusset notches (▽).
3. Finish the edges
   Zigzag or serge the side edges.

4. Sewing

4-1. Prepare the cord openings

1. From the top down to the casing line (dashed), fold the side seam allowances under to make the cord openings (opening stops).

4-2. Sew the sides

1. Fold at the base, right sides together, and sew each side up to the casing opening stop.
2. Leave above the openings unsewn; press the allowances open.

4-3. Box the base corners

1. Pinch each base corner into a triangle so the side seam meets the base fold.
2. Sew straight across the gusset line (▽ to ▽) at both corners; fold or trim the triangle tips.

4-4. Make the casing

1. Tidy the allowances above the opening stops and topstitch the openings.
2. Double-fold the top and stitch around to make the cord channel.

4-5. Thread the cords

1. Thread one cord from each side (both-side draw) and knot the ends; shape the bag.

5. Tips & variations

• Stands up: a deeper gusset holds a wider cup or box.
• Wipe-clean lining: line with laminate for food bags.
• Name tag: add a label for school.