How to make a round-base drawstring bag

1. Materials & tools

Materials (standard size)

• Main fabric (oxford, sheeting or printed cotton) — about 60 × 50 cm (24 × 20 in)
• Lining fabric — the same amount, if lining
• Cord (about 5 mm / ³⁄₁₆ in) — opening circumference + 20 cm each (about 67 cm at the standard size) × 2
• Bodkin

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” → “Round-base drawstring bag” from the tabs at the top.
2. Enter the size
   Enter the base diameter, bag height and the drawstring casing width. Presets cover a cup bag, standard, lunch size 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 base (a circle) and the body. Trace the circle accurately.
2. Cut
   Cut the base and two body panels, in main and lining if you are lining it.
3. Mark
   Transfer the four notches on the circle, the center notch at the lower edge of each body panel and the casing notches at the sides.
4. Finish the edges
   Unlined, zigzag the side and base allowances.

4. Sewing

4-1. Sew the sides, leaving the casing openings

1. Sew the two body panels together at both sides.
2. Stop each seam at the side notch (level with the lower line on the pattern, the stitching line) — those unsewn sections are where the cords come out.
3. Press the allowances open there and topstitch them down in a narrow rectangle. Backstitch at the point where the seam stops.

4-2. Attach the base

1. Pin the base to the lower edge of the tube, right sides together: match its four notches to the two side seams and the two center notches first, then fill in.
2. Sew with the circle uppermost, clipping the allowance every 1 cm.
3. Turn out and shape the base.

4-3. Make the casing

1. Turn the top edge under 1 cm, then fold again along the upper line on the pattern (the fold line) to make a double fold. Stitch along the edge of the double fold (the lower line on the pattern) all the way around. The unsewn side gaps open on the outside of the channel.
2. Check the channel connects to both side openings.

4-4. Thread the cords

1. Thread one cord in through one opening, all the way around, and back out the same opening. Knot the ends.
2. Thread the second cord from the other opening.
3. One cord from each side is what lets it close evenly by pulling both.

✏️ Both casing openings must stop at exactly the same height. Mark them on the two panels while they are stacked together, or the bag closes crooked.

5. Tips & variations

• Cup bag size: the cup preset matches the size daycares usually ask for.
• Interface the base: heavy interfacing on the base makes it genuinely self-supporting.
• Cord length: each cord is the opening circumference plus 20 cm for the knot (the pattern memo gives the length). Too short and it will not open fully.