Sew a foldable shopping bag easily

Magical moments await you every day in the BERNINA Advent calendar. “Create your Magic” is the motto and I’ve given you a little surprise for the seventh door of the advent calendar 2024. I’ve brought you a touch of magic for everyday life. I’ll show you how you can sew a foldable shopping bag without too much effort that magically transforms from “handy and small” to “practical and large”.

It doesn’t take much:

Light fabric without pattern direction: 75 cm x 100 cm (29 1/2″ x 39″)
Endless zipper caterpillar 4 mm: 80 cm, 2 matching sliders (31 1/2″)
Thin webbing 2.5 cm (1″) wide: approx. 130 cm (51″)
Elastic band 1.5 cm (1/2″) wide: approx. 25 cm (10″)

Let’s create your magic!

First press the two narrow sides (75 cm/ 29.5″)) of your piece of fabric 1 cm (1/2″) to the left and then another 3 cm (1″). Topstitch the envelope in place.

If your fabric, like mine, does not have a clear right side, you can also fold the fold/cover outwards. I did it this way because I like the look of the trim on the pocket opening.

Sew the zipper to the edges.
If you can’t get the zipper tucked under well, you can also fix it with a strip of WonderTape (narrow double-sided adhesive tape). However, make sure that you do not apply the adhesive strip directly in the seam area to prevent the needle from sticking.

Thread both sliders in opposite directions. Thanks to the two sliders, you can later decide how wide you want to open the foldable shopping bag.

Now fold the bag in half. On one side is the center of the zipper caterpillar, on the other side is a fabric book, which you mark with a small pinch.

Do a little math

Now we mark the folds. Measure the distance from the zipper to the break. Then divide the distance by four and you have the correct distance: Example distance 46cm (18″), divided by 4 – makes 11.5cm (4 1/2″) distance. Make the markings on both open sides of the bag and pin both layers of fabric together at the marking points using a cross needle.

Now sew the two layers of fabric together by about 1 cm (1/2″) at the markings. This small seam makes it easier to place the pleats.

Now it is folded. The best way to do this is on the ironing board. Place the first seam on the clip on the fabric fold and pin it to the backing.

Then the next seam follows, etc. Pinch the resulting fold breaks a little and make sure that the open edges of the fabric lie flush. Finally, the zipper is positioned in the middle of the pleat stack. Pin all the layers and sew them together about 1 cm from the edge. Folding is also done on both open sides.

Now we want to tidy up the crease breaks a little and if you like, you can iron them in lightly. To do this, grab the sides and pull the fabric apart a few times. Depending on the fabric, the pleats may lay evenly or you may have to help a little and align the layers of the foldable shopping bag a little.

Border edges of the foldable shopping bag

Now we are enclosing the open edges. To do this, measure the edges, double the result and add the allowance.
Example length 12 cm: x 2 = 24 + 2 cm allowance, results in a cut of 26 cm webbing (cut 2x). Or in inches: 4 1/2″ x2=9″+1″ results in 10″.

Close the pieces of webbing to form a ring and pinch the addition apart. Turn the whole thing over and sew one open side narrowly together, with the seam at the bottom in the middle.

On one side, grasp the elastic band between them. For the correct length of elastic, fold your shopping bag once to try it out and see how tight you want it. I used 25 cm (10″) of elastic.
Now slide the resulting end pieces over the open edges of the bag and sew through all the layers.

Once both sides have been edged, all that’s missing are the handles on our magic foldable shopping bag.

Final spurt

Cut two strips of webbing to the desired handle length. I took 30 cm (11 1/5″) and carefully melted the ends of the synthetic ribbon with a lighter. This meant I could sew the handles on in a single layer in the middle next to the zipper and didn’t have a thick seam. An X provides extra support.

Voila! The practical foldable shopping bag is finished, which is nice and small when not in use and offers generous storage space when unfolded.

You can find various instructions for this type of bag online. I actually found my inspiration in a plastic version I received as a gift from Asia. To ensure that the pleat magic also works with beautiful cotton fabrics, I have adjusted the amount and size of the pleats. And so that the project also works as a quick gift idea, I have dispensed with complicated ironing in of the individual pleat breaks, adjustable straps etc.