How to make a book bag (lesson bag)

1. Materials & tools

Materials (nursery standard (40 × 30))

• Main fabric (quilted cotton, oxford or canvas) — about 110 cm wide × 70 cm (44 × 28 in)
• Lining fabric (sheeting or light cotton) — the same amount
• Webbing for the handles (2.5–3 cm / 1 in wide) — the length you chose, × 2
• Optional: an appliqué or name label

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” → “Book bag (lesson bag)” from the tabs at the top.
2. Enter the size
   Enter the finished width and height, and the handle length and cut width. Presets cover the usual nursery size (40 × 30), small 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. Check the specified size
   Schools give it as height × width. Enter those numbers as they are — they are finished dimensions, not cutting dimensions.
2. Trace the pattern
   The body is a rectangle folded at the base, so mark it straight onto the fabric.
3. Cut
   Cut the body in main and lining, plus two handles.
4. Finish the edges
   Quilted fabric frays fast — zigzag the edges as soon as you cut, or sew straight away.

4. Sewing

4-1. Position the handles

1. Lay the main body flat and place the handle ends at the marked points on the opening edge, front and back.
2. Make sure the loops face outward, not inward — get this wrong and they end up inside the bag after turning.
3. Baste them 1 cm from the edge.
4. Do this while the fabric is still flat.

4-2. Sew the sides

1. Fold the main body at the base, right sides together, and sew both sides.
2. Do the same with the lining, leaving a 12 cm (5 in) gap in one side.
3. Press the seam allowances open.

4-3. Join the layers

1. Turn the main bag right side out and slip it inside the lining, right sides together.
2. Match the side seams to each other and pin, then sew all the way around the opening.
3. Backstitch two or three times where the handles are caught.

4-4. Turn and finish

1. Turn through the gap in the lining and close it by machine.
2. Push the lining inside, shape the opening and press.
3. Topstitch 5 mm from the opening edge so the lining cannot roll out.

✏️ The size a school gives is the finished size, and this pattern takes finished sizes too — so enter their numbers unchanged. Adding seam allowance yourself makes the bag a size too big for the locker, which is the most common mistake here.

5. Tips & variations

• Quilted fabric: enough body to stop picture books bending, and it survives daily use.
• Webbing handles: stronger and quicker than self-fabric, and they look right.
• Make the set: a shoe bag, a gym bag and a cup bag in the same fabric covers the whole nursery list.