Friday, October 7, 2016

Zip A Bag Chapter 25: Offset Welt-in-seam Zippered Purse

Finally, we've come to the last zippered bag in our series.


Ironically, this bag was one of the first of the series that I made. It was inspired by something I saw in Target (Target has some very interesting bags, construction-wise) a couple of seasons ago, and I wanted to make it while it was still fresh in my mind. 

I've saved it for last largely because of the asymmetry of the bag opening, which is a little unusual and not like any of the other techniques we've learned so far. 

See? It's like a tongue flapping open.

Let's walk through the features - a tubular carrying handle on the back

and an adjustable shoulder strap that inserts directly into the side seam.

Here is that zippered front panel opening 

and two zippered welt pockets: one on the back wall

and one in the outside wall.  

Also: piping. Very important, piping.

The sequence of adding piping to this bag was also unusual - the piping disappears into the side seam just under the shoulder strap insertion point but wraps around the side and top of the bag. 

Deconstructing the bag now.

First, the zippered welts. 

This back-wall zippered welt pocket is a standard organizational feature in the insides of my bags (the ones I'm not mass-producing for parties, I mean). Here is the tutorial

The zippered welt on the outside of the bag is done exactly the same way, except that it is on the outside and at an angle instead of horizontal. The pocket facing and lining pieces had to be cut to fit that tear-drop-shaped side wall but otherwise there's nothing extraordinary about this pocket at all.

Next is the front panel. This zippered welt is in-seam and off-set. Those are fancy terms, so I will explain them. 

Q: Whaddya mean - "in-seam"?
A: One half of the zipper tape is attached to the front flap itself in a sort of welt-pocket-looking way (see the end of the welt just above the vinyl panel at the bottom?) The other end of the zipper tape acts like a SA which is sewn directly into the seam that attaches the side wall to the main bag. There is piping also inserted into that seam, which distracts you from seeing the seam (so don't let it!). 

Q: Whaddya mean - "off-set"?
A: A zippered welt is a four-sided window into which a zipper is "set". Most of the time, these are rectangular welts (but there are also curved welts and other shapes which we are not concerned with today). This particular zipper is set into a three-sided welt, with the fourth side being the side seam itself. The resulting zippered opening looks 'off-set' from the seam; it is neither centrally located within the seam like in this pencil case

nor symmetrically within a floating welt like, well, regular zippered welts:

Let's move on to installing that zipper! It is easier than you think - remember these: 
  • we are going to make an "indentation" along the edge of the flap, called the "welt";
  • we are going to fill that indentation with the zipper 
  • to restore the flap's original dimensions
  • but with the zipper tape forming its new SA

All will be clear soon (one hopes).

Grit your teeth, friends, and follow along.

Begin with the lining. Our lining is a continuous piece that includes the flap, the curved base and the back wall of the bag. Mark the midpoints of the zipper and the short top edge of the lining. Align those midpoints as you lay the WS of the zipper on the RS of the lining as shown. Snip the zipper tape's SA touching the lining and in the two sections where it "turns" the corners of the flap. Baste the zipper tape in place to the lining. My stitching line is more angular around those corners than I initially planned, so I've basted the zipper a little farther from it.

Lay the outer fabric flap piece over that basting line so the RS of the two fabric layers are together. Note
  • the outer fabric piece is much shorter than the lining piece. We will add a vinyl panel to extend it later.
  • the two red arrows showing the end of the flap opening. These will be the end points of the zippered welt. 

Sew through all layers to attach that side of the zipper tape between the outer fabric and lining layers. 

Now we will finish the ends of the welt. Cut through both outer fabric and lining layers at an angle toward the end-points as shown, carefully avoiding the zipper tape between them.

Spread the fabric (both layers) apart to open that slit, and stitch them down across the zipper coils at a right angle to the original stitching line as shown. Do not fret if it looks like fiber massacre,

because when you turn everything RS out, you will get a beautiful welt corner. Here is the outer fabric side

and here is the lining side.

Repeat to finish the welt on the other end of the zipper - remember to move your zipper pull within the welt so it doesn't get "shut out"! This is what the lining side of the flap looks like.

Carefully turn out and press that welt seam, then edge-stitch close to the zipper to hold all the layers in place.  Can you see that while we've made an "indentation" in the flap to accommodate the zipper, the zipper itself has filled that space so that the flap+zipper is now the same size and shape as the flap before, with the free edge of the zipper tape forming its new SA? You can now attach other pieces to this flap/body piece .

This is the outer fabric side. On the bottom of the photo you can see a vinyl panel that has been attached to the outer flap piece.

Obviously, you can make the outer layer from a single fabric but if you choose to piece it like I have, the seams should remain in just the OUTER FABRIC layer, so that 
  • the stitches don't show on the lining side and
  • the lining and outer layers to remain separate except at the zipper where they meet.

To do this, simply lift the section of lining fabric under the zippered welt out of the way as you work on the outer fabric layer.

This is what the outer fabric side looks like now,

including the back piece that has the carrying strap inserted into a back seam.

Here are the two layers, now the same size. You can see the pocket innards on the WS of the lining layer, and the ends of the carrying strap peeking out on the WS of the outer fabric layer.

Schematic picture: the two layers are attached to each other along the zipper. Otherwise, they are separate.

And here is how the teardrop-shaped side wall attaches to the the main body -

working with each layer (outer fabric and lining) separately, sew the short top edges together to make a sideways cylinder. Then attach the teardrop-shaped side pieces to the open ends, incorporating the various straps and strap anchors into the seams as necessary. Leave a gap in the one of the lining seams through which to turn the entire bag RS out later.

Check out this bizarre thing!

Here is more helpful view:

See the zipper between the two bags - you can cut off the excess zipper tape if you want, but I left it as is.

Turn the whole bag RS out through the gap in the lining and stitch it shut. Here is the lining side out - a perfectly snug layer with no exposed (or bound) SA.

And here is the outside.

I omitted the piping sequence because it wasn't pertinent to the zipper-ness of this tutorial but even without, I thought this was by far the fiddliest bag of the entire series. Not only because of the zipper installation but also because of the thick layers of vinyl and interfacing (and piping!) that were tough to stitch through. But I love the finished product!

Next up: the epilogue post, in which I link to all the 25 chapters and we look back over the whole series and swoon (both in exhaustion and in delight) over what we've accomplished!


  1. Wow! Espectacular bag! Thank you for sharing it with us!

  2. I had to try making this amazing bag, even though you warned us about the 'not-so-easy' sewing... I finally made it, and it even turned out nice :) Thank you for the instructions! And for the zip a bag series in general, I really enjoyed and learned from it!

    As I understood it, in the front panel welt zipper, the indentation is the seam allowance. The 1 cm I usually use was too small for me. If I dare to sew this bag again I will use a bigger seam allowance for this part...

    1. Please could you tell me where to purchase this pattern My email is Thanks so much.

    2. I Love this Purse!!! Thanks so much.


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