1. Decide your seam. Unlined bag: French seams, so every edge ends up enclosed. Lined bag: plain seams, because the lining will hide them. The steps below assume the unlined French-seam bag; the lined version is in the variations fold.
2. First pass of the French seam. Fold the piece wrong sides together (yes – wrong sides: the French seam starts backwards) and sew both sides with a 5 mm seam, from the fold up to the 6 cm notch, backstitching at the notch. Look for: stopping exactly at the notch, not past it.
3. Trim and turn. Trim both seams to 3 mm, turn the bag wrong side out, and press the seams so the stitched line sits right on the edge.
4. Second pass. Sew both sides again at 7 mm, enclosing the raw edges inside the seam, again from the fold to the notch (Module 6, Enclosed seams: French and flat-felled). Look for: no whiskers of raw edge escaping on the right side – if any show, the second pass was too shallow.
5. Finish the casing openings. Above the notches, 6 cm of side edge is still raw and open on each side. Press each raw edge under 5 mm and stitch a small rectangle around each opening through the pressed edges, pivoting at the corners. Look for: a flat, reinforced opening – this is where the drawstring will saw back and forth for years.
6. Make the casing. With the bag still wrong side out, press the top edge down 1 cm, then 3 cm, all the way round – a deep double-fold hem (Module 6, Hems by machine). Pin, then stitch close to the lower fold, right round the bag, keeping the side-seam allowances pushed open flat. Add a second row 3 mm from the top fold for crispness. Look for: an even casing depth all round; the cord needs a clear channel.
7. Turn right side out and press the whole bag, corners pushed out gently.
8. Thread the drawstrings. Pin the safety pin through one end of the first cord and work it in through the left opening, right round the bag, and out of the same opening. Knot its two ends together. Thread the second cord from the right opening the same way, and knot. Look for: both knots sitting outside their own openings; pulling the two knots apart should gather the top from both sides at once.
9. The stretch goal: boxed corners. Turn the bag inside out again. At one bottom corner, pinch the side seam and refold the corner so the seam lies along the centre of a flattened triangle. Measure 4 cm from the point along the seam, draw a chalk line across at right angles (the line will be about 8 cm long), stitch along it twice, and trim the triangle to 1 cm – or zig-zag and leave it for strength. Repeat on the other corner. Look for: both chalk lines the same distance from their points, or the bag will stand lopsided.
10. Final check. Turn out, press, pull the strings, and load the bag with something real – a pair of shoes, three oranges. Look for: seams that hold, a top that gathers evenly, corners that let it stand.

• Mark the notches before anything else. Every later step depends on the casing openings being level with each other.
• French seams love a press. Press after the first pass, before the second – the enclosed edge comes out knife-sharp.
• Remember the backwards start: French seams begin wrong sides together. Pin a note to the machine if you must.
• Scorch-test the casing depth: your cord, doubled, must slide easily through the channel. A 3 cm casing suits cord up to about 8 mm.
• No bodkin? A safety pin leads the cord; a straw over the cord’s end also works for stiff nada.
• Melt-proof the cord ends – knot cotton cords, or bind the last 1 cm with thread, before threading. A frayed end jams in the casing.
• Two strings beat one. One string closes a bag; two strings opposing close it tight and make carrying loops.
• Sew the casing from the right side if your lower-fold stitching wanders – you can see the line the world will see.
• Box corners the same evening you learn it, on a scrap folded like a corner, before the real bag.
• Batch-cut three bags at once. Bags two and three take under an hour each, and gifts are solved for the season.

Raw threads peep out of the French seam on the right side.

1. Sew the second pass again, 2 mm deeper, enclosing the strays.
2. If the seam is already bulky, trim the whiskers close with sharp scissors and run a second line of stitching to secure.
3. Prevention: trim the first pass to 3 mm everywhere before turning – it is the untrimmed patches that escape.

The drawstring will not pull through the casing.

1. The channel is blocked at a side seam: unpick the few casing stitches there, push the seam allowance flat open, and re-stitch.
2. The safety pin came undone: use a bigger pin, pinned through the cord twice.
3. Prevention: press the side-seam allowances open above the notches before folding the casing, and keep the casing a size generous for the cord.

The casing twists or varies in depth, so the cord binds.

1. Unpick the narrow stretch, re-press the 1 cm + 3 cm folds with a chalk guide line, and re-stitch.
2. If only slightly tight, a second row of stitching a touch lower can re-open the channel.
3. Prevention: press the casing folds with a measured chalk line rather than by eye, and pin every 5 cm.

The casing openings fray with use.

1. Work close blanket stitch or a machine zig-zag around the opening to bind the fray.
2. If badly frayed, unpick, trim back, press under a fresh 5 mm and re-stitch the rectangle with a shorter stitch.
3. Prevention: always stitch the reinforcing rectangle at step 5; it is the step impatient sewers skip, and the first place a bag dies.

The boxed corners come out unequal, and the bag stands crooked.

1. Measure both triangles from point to stitching; unpick the odd one and re-stitch at the matching measurement.
2. Check the side seam was centred on the triangle – an off-centre seam skews the corner even when the measurement is right.
3. Prevention: mark both corners with chalk and measure twice before stitching either.

The top gathers unevenly – bunched at the openings, flat at the back.

1. Work the gathers round the casing by hand, like evening out curtain gathers.
2. Check the cords did not cross inside the channel; re-thread one if they did.
3. Prevention: thread each cord in and out of its own opening, right round the bag, and knot before threading the second.

• Lined version: sew bag and lining separately with plain 1 cm seams (leaving a 10 cm turning gap in one lining seam), drop the bag inside the lining right sides together, sew round the top, turn through the gap, close the gap as in Project 1’s ladder stitch, press, and stitch two parallel lines round the top – 2 cm and 5 cm down – to make the casing between them. Openings are buttonholes or small eyelets worked before joining.
• For women: a small lined version in soft silk or chanderi, 15 × 18 cm, is a jewellery or bangle pouch for travel.
• For men: a tall bag, 20 × 45 cm in canvas, carries an umbrella or badminton racquet; a 35 × 40 cm one in heavy cotton is a laundry or gym-shoe bag.
• For children: a 30 × 35 cm bag with the child’s name in running stitch makes a school activity bag; use flat tape, not cord, for small hands to grip.
• Shopping bag: size up to 40 × 45 cm in strong cotton, box the corners at 6 cm, and use wide nada doubled – it folds to nothing in a handbag.
• For gifting: a fabric gift bag replaces wrapping paper and becomes part of the present. Sew a set in festival colours; add a Kasuti border or running-stitch rows for the top fold to show when open.

• Starting the French seam right sides together out of habit, then finding the raw edges on the outside.
• Sewing the side seams all the way to the top, sealing the casing openings shut.
• Stitching the casing channel through a flapping seam allowance, blocking the cord.
• Threading the cord before reinforcing the openings, then wondering why they fray.
• Boxing corners by eye. Four centimetres on one corner and five on the other shows from across the room.

• Press the finished bag flat with the cords pulled out straight, not bunched.
• Knot or bind the cord ends permanently once you are happy with the length.
• Wash as the cloth allows; pull the casing straight while damp so it dries unwrinkled.
• If a cord ever frays inside the casing, pin the new cord to the old one’s end and pull it through – the old cord is the threading tool.

• Did your side seams stop exactly at the casing notches?
• Is every raw edge enclosed or bound somewhere?
• Do both cords run freely and gather the top evenly?
• Are the casing openings reinforced?
• If you boxed the corners, are both triangles the same measurement?

Five yeses: casings hold no mystery, and the waistband in Project 4 is just a casing on a garment.