Tuesday, February 9, 2016

Zip A Bag Chapter 13: Collapsible Drum

The next few posts are of a new category of bag zipper configuration - the zippered gusset.
Zippers can be inserted into gussets in many ways. Here are four (clockwise from top left):
  • central, with fabric stop
  • offset (side) with fabric stop
  • zipper-as-gusset, externally bound
  • offset, seam-to-seam

While they look different, their construction is similar, and once you've learned the concept, you'll be able to make all kinds of zippered gussets. They're easier than they look!

Today's bag is one of my favorites.

For one, it's ROUND, which is the best shape in the world, 

and has these straps that you can play around with

 to carry the bag in different ways,

like this:

This is the particular configuration that inspired its name.

For another, its construction sequence makes me happy because it appeals to the part of me that likes puzzles and method and logic. It's the kind of sequence that gives you a fully-lined interior for both the main body and lid,

with all the seam allowances hidden between lining and outer layers. 

And did I mention that it has a zippered base,

(whose SA are also all hidden away)

that, when unzipped,

lets this bag collapse

and fold completely flat?

Bags like these are why I put up with Math and Science lessons in school when I really would've preferred to be reading or writing or - better yet - swimming or hanging out at the beach. 
(Not much has changed.)

Anyway, let's talk about this bag. This is a simple bucket tote. It has a hinged lid. Which is zippered. Not a big deal.

Now, if were were sewing it the commercial way i.e. sewing both outer and lining together as a single layer, with all the SAs exposed on the inside of the bag, which are then bound with bias tape or trim, it could absolutely be a Beginner Level kind of sewing project. In the next post, we'll be making a pouch with that exact method, for completion's sake.

In this post, however, we'll be making this lidded bucket tote the More Elegant Way - with invisible SA. The construction process isn't quite as linear, which might bump it up into the Intermediate Level category and require a little more visualization. But I took lots of pictures, so hopefully we won't lose anyone along the way.

Some notes:
  1. The zippered base is constructed exactly the same way as the one in the last post. We always install the zipper along the longest dimension of the base. In a square or rectangle, this is its diagonal. In a circle, this is the diameter.
  2. Beside the outer and lining, there are layers of stabilizers to provide support, including a heavy sew-in interfacing for the lining and headliner (or the more pricey Flex-Foam) for the outer.
  3. The outer body is Jessica Jones' Timewarp Navy Ripple barkcloth pieced with with a textured sand upholstery vinyl, which I also used for the straps. The outer base and piping are a navy canvas and twill, respectively. The lining is some chrome yellow quilting cotton whose designer I've forgotten (sorry!) paired with a natural canvas base.

STAGE 1: Make the straps
These are normal Truly-Reversible Closed-Ended straps,  

into which are incorporated lobster-claw-type snap hooks. See this post for how to make them.

They snap together to create a long shoulder strap.

Because this joint can be annoying digging into your shoulder, I made a sliding sleeve,

like so:

Four short strap anchors with D-rings are inserted into the main mid-body seam,

for the straps to latch onto.

STAGE 2: Make the base
The circular base is cut as two semicircles (with appropriate SA) for each layer (outer, inner, and the applicable stabilizers). Face the zipper the usual way. I began with the base lining,

then layering the base outer fabric over that,

on top of which I added some stabilizer (headliner) - even with the two layers of canvas, I felt the base needed some structure.

Repeat to face the other side of the zipper tape. so you get a complete circle. Topstitch/edge-stitch on either side of the zipper to finish. Note that the zipper is deliberately sewn so that its zipper pull is on the lining side of the base (i.e. the WS of the completed base sandwich) - this is because we want to access it from the inside of the bag.

Here is the completed base sandwich. I basted along its circumference to hold all the layers together.

STAGE 3: Assemble the body
In this stage, we'll be making two cylinders, one for the outer body, and the other for the lining. If you want to pipe the base, add piping to the bottom edge of the outer body cylinder now. To draft a body cylinder, see this post and this post

Now, we'll attach the base sandwich. This part is a bit funky if you're not used to spatial visualizing, but this is what we're aiming for - the bottom circumferences of both cylinders attached to the base, which then sits between them.

This tutorial might help you. 
Essentially, this is the sequence:
  1. Attach the base to the bottom opening of the lining body. The lining body's RS should be touching the lining side of the base sandwich.
  2. Attach the base to the bottom opening of the other cylinder (i.e. the outer). The outer body's RS should be touching the outer side of the base sandwich. In theory, you'll be sewing on the same stitching line as before, because you're attaching both cylinders around the same circumference of the same base sandwich. You'll also have to push the first cylinder into the middle of the circle to be out of the way of the base's circular edge while you attach this second cylinder. Fortunately, this bag has that zipper in the base, so you can unzip it and shove the lining through it:

Turn everything RS out to check.

Done correctly, the outer side of the bag will look like this:

And the inside of the bag should look like this. See: no SA visible around the base outline; they're all tucked between the layers.

The ickiest part of constructing this bag is done. Pats on the back!

STAGE 4: Prep the main zipper
This is the same thing as you do to any zipper that needs fabric stops. Except that this fabric stop is extra long, and attaches to the zipper at both ends to make a zipper loop. This loop must fit the circumference of the cylinder and lid EXACTLY, so measure your zipper and fabric stop lengths accurately. If you're insecure about getting it exactly right in the cutting stage, cut the fabric stop pieces longer than you need - you can always trim them down later.

So go ahead and prep one end of the zipper.

Now sandwich the other end of the zipper between the remaining short ends (RS together) of the fabric stop, and sew the seam that secures it in place. In the photo above, you can see a light blue mark on the tan vinyl where I've measured the exact position of the seam. There might be a bit of twisting of the fabric stops to make this happen, but they're long enough for you to maneuver them relatively easily. 

Done correctly, the final prepped zipper should look like this, complete with topstitching.

STAGE 5: Construct the lid
Here's an overview photo to show the layers of the lid- they're the same as for the body cylinder. Don't sew all these layers together at once - separate them into the outer layer(s) and the lining layer(s).

We're now going to attach the zipper loop to the lid. If you were planning on piping the lid, attach the piping now to the zipper.

A note about piping: at a seam between a straight edge and a curved edge, we always attach piping to the straight edge first, and then ease that straight edge around the curved edge. So when attaching a cylinder to a circular base, we attach the piping to the opening of the cylinder (straight edge) and then curve that opening around the circumference of the circular base (curved edge).

So, too, with this lid. The zipper tape is the straight edge, so the piping goes on that first.

Here's the big-picture plan:
And now we'll attach that piped-zipper-tape around the circumference of the outer lid -

one side of the zipper tape sewn on, and the other side left free, to attach to the body later.

Now coil that free zipper tape back into the middle of the lid so it's out of the way and layer on the lining layer(s). Sew all around, leaving a gap for turning out.

Hand-stitch that gap shut. 

You will now have a perfectly lined zippered lid, with no SAs visible on the lining side

or the outside.

STAGE 6: Attach zipper to body

Sew the free side of the zipper tape to the top rim of the lining body, so that
  • the coils point downwards
  • the WS of the zipper tape (i.e. the lining side of its fabric stop) is in contact with the lining body
  • the fabric stop is directly above either the head or tail end of the base zipper.

Here is the view from the other side of the cylinder.

STAGE 7: Bring the layers together

Here is the sequence for this last stage.

First, fold down the SA of the lining cylinder to its WS as shown. This will flip the coils of the zipper tape up. 

Next, flip the outer cylinder up over the WS of the lining cylinder, to bring their top  openings together. Their WS are now in contact, and the bag looks almost finished. Fold the SA of the outer cylinder down to its WS, as shown.

Topstitch/edge-stitch all around the opening of the bag, through both the lining and outer layers, to attach them together. If you use the stitching line from Stage 6 as your guide, 

you should be able to stitch on the outer side of the bag

and neatly and uniformly "catch" the lining fold on the inside.

The bag is now finished!


  1. Very useful tutorial...will make one bag like this

  2. Total lightbulb moment. I have been trying to make lined circular earbud pouches with the zip going around the perimeter and a fabric stop acting as the hinge between the top and bottom sections. I couldn't figure out how to do the fully lined circle with the zip in-between. This is exactly what I needed. Thank you so much.

  3. This is a very clever bag. I love the drum-style bags but they take up too much storage space when they don't collapse like this.

  4. Thanks for the tutorial. I love how math and creativity are perfect for each other. What a great couple!

  5. I'm thoroughly enjoying your zipper tutorials. Not everyone who sews and crafts can also teach but you have a great talent for both and your instructions and photographs are much easier to understand and follow than some books I've seen. The fact that you're also sharing these techniques for free is a fantastic bonus for us blog readers. Thank you!

  6. Even though I have not created one of your bags, I did enjoy reading your tutorial and looking at the detailed illustrations. Well done...I will be back to read more of your posts!


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