Wednesday, March 7, 2018

photo tutorial: Fully lined pyramid bag with tab and zip stop

So in my last post (October! So long ago!), I talked about pyramid bags and why I thought the tutorials I could find were not ideal. I thought about it for a while, and have figured out how to do a fully lined, no raw seam showing, folded zipper pyramid bag with a zip stop and a pull tab. It is possible to put in a top tab as well, but I didn't here. I mention how in the cutting instructions. This is a bit of a fiddly/tricky construction, but it's not all that difficult, and I really think it's worth taking the extra time to get the result I wanted.




This size comes out at not quite 15cm (6") wide, and the front face is a bit under 12cm (4.25") tall. Adjusting the size is trickier than I expected, because I haven't thought about the geometry of equilateral triangles for a long time (more on that later).

Please excuse the water stains on my ironing board. And the cat hair fuzz, I didn't feel like pulling out the lint remover thingy.

Also, most of the measurements I use are in cm because that's what my quilting ruler does. However, my sewing machine throat plate is marked in 1/8" increments, so mostly I talk about the seam allowances in inches. But the measuring is in cm. 3/8" is just a hair under 1cm, so I cut with 1cm allowances. Pretty much all the seam allowances are 3/8" so I'm not going to bother saying it every single time.

Cut:
- Outer fabric (blue): 26cm x 15.75cm (I rounded up to 16cm because my ruler only has half cm marks)
- Lining fabric (yellow): 26cm x 15.75cm (again I rounded up)
- Fusible fleece: 24cm x 15cm
- Zipper tape: 24cm
- Pull tab (red): 3.5cm (W) x 7cm (H)
- Zip stops (red, cut 2): 3cm (W) x 4cm (H)
- You will also want a zipper pull



Directional fabrics: On a print such as mine, where there is no top or bottom, cut so the long side is aligned with the vertical of the print (unless you want, say, horizontal stripes). On a directional fabric where there is a top and a bottom, cut two 14cm x 16cm, with the 14cm along the grain (vertical of print). Place wrong sides together, with the top of the print together, and sew with a 1cm (3/8") seam allowance along the top. Press seam open; you should have a rectangle 26cm x 16cm, and the "up" of the print should be pointing into the middle. There will be a seam down the back edge of the finished bag.

Optional: If you want to do a top pull tab (like the larger owl bag in my last post), cut as for a directional fabric, make an additional pull tab, and sew it into one end of the joining seam, maybe half an inch or an inch in from the corner. When assembling the bag, make sure the top pull tab is on the same side as the zipper.

Optional: You can cut the fusible fleece to the full size of the outer fabric. It makes the seams a bit more bulky, but it doesn't make a huge difference. Or you can  cut it 1cm narrower and fuse it centered to eliminate bulk at the zipper; I like the slight poofiness at the edge of the zipper.

Optional: Do some quilting on the outer fabric once the fleece is fused. Or do it for sure if you're using not-fusible fleece.

Fuse fleece to outer fabric, with one long edge aligned and 1cm gap around the other three sides.

Fold long edges of pull tab towards center (1/4") and press. Fold in half crosswise, and press. Fold down 1cm of zip stops, press.


Topstitch sides and folded edge of pull tab


Place zipper along the long edge of outer fabric that has the fleece all the way to the edge, right sides together. Mark ~2cm from either end of the zipper, then stitch down between these lines with a 3/8" seam allowance.


Place lining fabric, right side down, on the outer+zip piece, and stitch along zipper (as before, between the marks, 3/8" seam allowance).


Flip the fabrics around and press so that the zipper edge is protruding.


Here comes the first tricky bit. Fold the short edges in towards the middle so the zipper looks like a zipper, and finesse the zipper pull onto the zipper. Ikatbag is an excellent blog, and she talks about single zipper tapes here if you want/need more information about how this works. The zipper will almost always be slightly offset; because of this, if you want your print to be exactly perfectly aligned symmetrically across the zipper, this is probably not the best technique for a pyramid bag. However, you can get pretty close. Just be aware that the more you undo and retry getting the zipper pull on, the more the edges of the zipper tape will fray and the more difficult it becomes, so you'll have to trim down the tape. Cut the zipper tape with extra length to start with if you think you might want to do this.


Now the next fiddly bit. Fold up the outer and inner fabric from the ends of the zipper tape (remember how we didn't stitch down all the way to the ends of the tape? this is why). Take your two zipper stop pieces, and align them with the end zipper tape. Take a look at the ikatbag tutorial, under heading "stage 1: fabric stops." We're pretty much doing the same thing here, but there's fabric already attached to the zipper so it just looks messier.




Next tricky-ish bit. Fold the outer and lining fabric down to make a triangle. The zipper stop will protrude a bit, we'll trim it later. Take your time to make sure the loose bits of the main fabrics are nice and straight along the bottom of the zipper and zipper stops, pin or WonderClip them if necessary. We're going to topstitch the zipper. This is kind of awkward. I like to turn the bag inside-out(ish) so that I'm working from the public side of the bag. Starting at one side of the zipper, topstitch all along the zipper. When you're about 2/3 of the way up towards the top of the triangle, put the needle down, lift the presser foot, and finesse the zipper completely open. Put the presser foot back down, and continue to stitch along the edge, manipulating the bag as needed. When you're close to done, lift the presser foot again with the needle down, and close the zipper. This is one continuous line of stitching.






Trim the zipper stops.


Flip the bag out so that the zipper is in the middle and the outer and lining pieces are to either side.


Stitch along the side of the outer piece (3/8" seam allowance, which should be right along the edge of the fleece). Clip the top corner. Stitch HALF the lining, with a 1/2" - 5/8" seam allowance (because once you flip things right side out in the end, the lining always seems to be too big and is wrinkly, and this helps minimize that. I suppose I could cut the lining smaller to start with but I never think to do it). LEAVE A GAP for turning.


This next bit is rather three-dimensional and I'm not sure if I'll be able to explain it very well but it's easy to do. Take those seams you just sewed, and align them with the zipper, so the open bottom ends of the bag are folded to either side. Press the just-sewn seams open (just an inch or so, doesn't need to be all the way). Take the pull tab, and tuck it in between the zipper and the outer fabric, with the raw edges aligned and the "good" end of the pull tab facing in. Oh, and OPEN THE ZIPPER. Don't be like me and save yourself some grief later.




Now line everything up nice and neatly and sew all the way across that open end, through all the layers. This is why the fleece is cut smaller, and the zipper is a bit shorter and has a zip stop, it makes it a lot easier to sew this bit, and eliminates a lot of bulk in the final bag so that bottom front middle  is nice and neat.




Clip the outer corners of the seam that was just sewn. Optionally (less optional if you have zipper tape or the fleece in this seam), grade the outer fabric part of the seam allowance. You could grade all the seams if you want to, but I don't think it's necessary.


Almost done! Find the gap in the lining, and turn the bag right-side-out. This is where having the zipper open *before* sewing that last seam is a good idea. If you didn't, you'll just have to find the zipper pull through the layers of outer  fabric and fleece, and manipulate it open. Doable but annoying.




Pull the lining back out, turn and press the gap (just like any other pull-the-bag-through-the-lining bag), stitch closed by machine or by hand. I personally prefer by hand.



Replace the lining back in the bag, gently press the seams for a neater finish (that blue/white/grey thing on the right is my iron), and voila! You have a bag!



To enlarge the bag, you can do one of two things. Either fudge it (until I thought to double check actual geometry, I was cutting the fabric in rectangles that were twice as long as they were wide (which is what many of the tutorials say to do), and that works pretty well, but the smaller the bag, the more obvious it is that it's not quite an equilateral triangle). Otherwise, an equilateral triangle has a height of h and a base of a. The finished zipper length corresponds to h, and the length of the sides is a. Figure out what you want those numbers to be. The rectangle you cut will be (2h+2SA) x (a+2SA), where SA is the seam allowance (1cm for me), and the single-sided zip length is 2h. The zip stops and pull tab can stay the same, or be increased if desired.

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