Here are the instructions for making your shopping bags from an existing plastic bag as a pattern. As I mentioned before, I liked the shape of the container store bag for its height and thickness of making the pattern, but any bag will do… This one worked particularly well, as it fit nicely on a 45″ piece of fabric. It was nearly exact, and used a bit less than 3/4 yard remnants.
Cut the bottom seam and handle seams open on your bag, removing the part where the bag is fused. Slit the bag down one side inside the crease. Trace the bag with seam allowances – I used 5/8″ because of the french seaming and double sewing in the handles.
Cut your bag out. You will need both a lining and an exterior. For this example, I’m using the rainbow fabric for the outside and plain blue dye for the inside – this will keep things clear (I hope!).
First, sew your side seams.
Then for the curved part connecting the handles.
Trim them nicely, turn right side out and press.
You will now have a tube with 4 “legs”.
Now, this step is not necessary, but it helps me from ending up with a jumbled mess. Find your handle portions by looking for the narrow curved connector. You will sew together the two legs of the narrow connector (I had to tear out the seams of at least one bag before I had this epiphany). Take the two legs and sew them together on the inside at the edge – doesn’t matter if you pick inside or outside fabric – this is just a sewn tack for when you flip the bag. Repeat on the other set of legs.
Now for the tricky bit. We will now flip the bag so that the right sides of the fabric are together again, like when we were sewing the legs. You will pull the legs through too.
Now, where you tacked the handles together will show up as a round tube.
You are going to sew around the tube, as demonstrated here.
I remember this was always called “sewing around the teacup”, but I can’t remember where I learned that. I sew at 3/8″ and 5/8″, then serge the edge.
Your handle seam will be nice and professional looking when you put the bag back to wrong sides together. Press.
Edge stitch the handles at this point, about 1/4″ from edge.
You should then fold the handles, so that the side will crease, the outside edge being folded underneath. Stitch in the ditch at the top seam to hold them together.
Using your folded handle as a guide, crease the bag portion with a gusset on both sides and press. Sew the bottom of the bag from the outside as shown below at a small seam allowance, appr. 1/4″.
Trim the excess, and flip it to the inside, taking care to keep the gusset folds straight.
Sew again at a deeper seam allowance, appr. 3/8″ in a french seam. Flip your bag back to the outside, and your done!
Initial tests of this bag show that they hold well more than the standard paper grocery bag, about 50% more, most likely due to the size of the original bag used as the template.